1.18.2 RB 3

https://forums.minecraftforge.net/topic/149549-forge-403-minecraft-1182/

.gitignore

@@ -33,7 +33,6 @@
 /projects/**/*.launch
 /repo/
 src/generated/resources/.cache/
-src/generated_test/resources/.cache/
 
 #Patch rejects
 /patches-/

.teamcity/settings.kts

@@ -1,5 +1,7 @@
 import jetbrains.buildServer.configs.kotlin.v2019_2.*
 import jetbrains.buildServer.configs.kotlin.v2019_2.projectFeatures.githubIssues
+import jetbrains.buildServer.configs.kotlin.*
+import jetbrains.buildServer.configs.kotlin.v2019_2.buildSteps.gradle
 
 /*
 The settings script is an entry point for defining a TeamCity
@@ -30,11 +32,13 @@ project {
     buildType(Build)
     buildType(BuildSecondaryBranches)
     buildType(PullRequests)
+    buildType(PullRequestChecks)
+    buildType(PullRequestCompatibility)
 
     params {
         text("docker_jdk_version", "17", label = "Gradle version", description = "The version of the JDK to use during execution of tasks in a JDK.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
         text("docker_gradle_version", "7.4", label = "Gradle version", description = "The version of Gradle to use during execution of Gradle tasks.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
-        text("git_main_branch", "1.18.x", label = "Git Main Branch", description = "The git main or default branch to use in VCS operations.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("git_main_branch", "1.19.x", label = "Git Main Branch", description = "The git main or default branch to use in VCS operations.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
         text("git_branch_spec", """
                 +:refs/heads/(main*)
                 +:refs/heads/(master*)
@@ -134,3 +138,71 @@ object PullRequests : BuildType({
         """.trimIndent()
     }
 })
+
+object PullRequestChecks : BuildType({
+    templates(AbsoluteId("MinecraftForge_BuildPullRequests"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"))
+    id("MinecraftForge_MinecraftForge__PullRequestChecks")
+    name = "Pull Requests (Checks)"
+    description = "Checks pull requests for the project"
+
+    steps {
+        gradle {
+            name = "Check"
+            id = "RUNNER_10_Check"
+
+            tasks = "checkAll"
+            gradleParams = "--continue %gradle_custom_args%"
+            enableStacktrace = true
+            dockerImage = "%docker_gradle_image%"
+            dockerRunParameters = """
+                -v "/opt/cache/agent/gradle:/home/gradle/.gradle" 
+                -v "/opt/cache/shared/gradle:/home/gradle/rocache:ro"
+                --network=host
+                -u 1000:1000
+                %docker_additional_args%
+            """.trimIndent()
+        }
+    }
+
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})
+
+object PullRequestCompatibility : BuildType({
+    templates(AbsoluteId("MinecraftForge_BuildPullRequests"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"))
+    id("MinecraftForge_MinecraftForge__PullRequestCompatibility")
+    name = "Pull Requests (Compatibility)"
+    description = "Validates binary compatibility for pull requests made to the project"
+
+    steps {
+        gradle {
+            name = "Validate"
+            id = "RUNNER_10_Compatibility"
+
+            tasks = "checkJarCompatibility"
+            gradleParams = "--continue %gradle_custom_args%"
+            enableStacktrace = true
+            dockerImage = "%docker_gradle_image%"
+            dockerRunParameters = """
+                -v "/opt/cache/agent/gradle:/home/gradle/.gradle" 
+                -v "/opt/cache/shared/gradle:/home/gradle/rocache:ro"
+                --network=host
+                -u 1000:1000
+                %docker_additional_args%
+            """.trimIndent()
+        }
+    }
+
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})

Jenkinsfile

@@ -1,125 +0,0 @@
-@Library('forge-shared-library')_
-
-pipeline {
-    options {
-        disableConcurrentBuilds()
-    }
-    agent {
-        docker {
-            image 'gradle:7-jdk16'
-            //args '-v forgegc:/home/gradle/.gradle_cache/'
-        }
-    }
-    environment {
-        GRADLE_ARGS = '--no-daemon --console=plain' // No daemon for now as FG3 kinda derps. //'-Dorg.gradle.daemon.idletimeout=5000'
-        DISCORD_WEBHOOK = credentials('forge-discord-jenkins-webhook')
-        DISCORD_PREFIX = "Job: Forge Branch: ${BRANCH_NAME} Build: #${BUILD_NUMBER}"
-        JENKINS_HEAD = 'https://wiki.jenkins-ci.org/download/attachments/2916393/headshot.png'
-    }
-
-    stages {
-        stage('notify_start') {
-            when {
-                not {
-                    changeRequest()
-                }
-            }
-            steps {
-                discordSend(
-                    title: "${DISCORD_PREFIX} Started",
-                    successful: true,
-                    result: 'ABORTED', //White border
-                    thumbnail: JENKINS_HEAD,
-                    webhookURL: DISCORD_WEBHOOK
-                )
-            }
-        }
-        /*
-        stage('pull_cache') {
-            steps {
-                sh 'cp -r /home/gradle/.gradle_cache/jdks/ /home/gradle/.gradle/jdks/'
-                sh 'cp -r /home/gradle/.gradle_cache/wrapper/ /home/gradle/.gradle/wrapper/'
-                sh 'cp -r /home/gradle/.gradle_cache/caches/ /home/gradle/.gradle/caches/'
-            }
-        }
-        */
-        stage('setup') {
-            steps {
-                withGradle {
-                    sh './gradlew ${GRADLE_ARGS} --refresh-dependencies --continue setup'
-                }
-                script {
-                    env.MYVERSION = sh(returnStdout: true, script: './gradlew :forge:properties -q | grep "^version:" | cut -d" " -f2').trim()
-                    env.FMLONLY_VERSION = sh(returnStdout: true, script: './gradlew :fmlonly:properties -q | grep "^version:" | cut -d" " -f2').trim()
-                }
-            }
-        }
-        stage('changelog') {
-            when {
-                not {
-                    changeRequest()
-                }
-            }
-            steps {
-                writeChangelog(currentBuild, 'build/changelog.txt')
-            }
-        }
-        stage('publish') {
-            when {
-                not {
-                    changeRequest()
-                }
-            }
-            environment {
-                CROWDIN = credentials('forge-crowdin')
-                KEYSTORE = credentials('forge-jenkins-keystore-old')
-                KEYSTORE_KEYPASS = credentials('forge-jenkins-keystore-old-keypass')
-                KEYSTORE_STOREPASS = credentials('forge-jenkins-keystore-old-keypass')
-            }
-            steps {
-                withCredentials([usernamePassword(credentialsId: 'maven-forge-user', usernameVariable: 'MAVEN_USER', passwordVariable: 'MAVEN_PASSWORD')]) {
-                    withGradle {
-                        sh './gradlew ${GRADLE_ARGS} publish -PkeystoreKeyPass=${KEYSTORE_KEYPASS} -PkeystoreStorePass=${KEYSTORE_STOREPASS} -Pkeystore=${KEYSTORE} -PcrowdinKey=${CROWDIN}'
-                    }
-                }
-            }
-            post {
-                success {
-                    build job: 'filegenerator', parameters: [string(name: 'COMMAND', value: "promote net.minecraftforge:forge ${env.MYVERSION} latest")], propagate: false, wait: false
-                    build job: 'filegenerator', parameters: [string(name: 'COMMAND', value: "promote net.minecraftforge:fmlonly ${env.FMLONLY_VERSION} latest")], propagate: false, wait: false
-                }
-            }
-        }
-        stage('test_publish_pr') { //Publish to local repo to test full process, but don't include credentials so it can't sign/publish to maven
-            when {
-                changeRequest()
-            }
-            environment {
-                CROWDIN = credentials('forge-crowdin')
-            }
-            steps {
-                withGradle {
-                    sh './gradlew ${GRADLE_ARGS} publish -PcrowdinKey=${CROWDIN}'
-                }
-            }
-        }
-    }
-    post {
-        always {
-            script {
-                archiveArtifacts artifacts: 'projects/forge/build/libs/**/*.*', fingerprint: true, onlyIfSuccessful: true, allowEmptyArchive: true
-
-                if (env.CHANGE_ID == null) { // This is unset for non-PRs
-                    discordSend(
-                        title: "${DISCORD_PREFIX} Finished ${currentBuild.currentResult}",
-                        description: '```\n' + getChanges(currentBuild) + '\n```',
-                        successful: currentBuild.resultIsBetterOrEqualTo("SUCCESS"),
-                        result: currentBuild.currentResult,
-                        thumbnail: JENKINS_HEAD,
-                        webhookURL: DISCORD_WEBHOOK
-                    )
-                }
-            }
-        }
-    }
-}

build.gradle

@@ -1,4 +1,11 @@
+import de.undercouch.gradle.tasks.download.Download
 import groovy.json.JsonBuilder
+import net.minecraftforge.forge.tasks.checks.CheckATs
+import net.minecraftforge.forge.tasks.checks.CheckExcs
+import net.minecraftforge.forge.tasks.checks.CheckPatches
+import net.minecraftforge.forge.tasks.checks.CheckSAS
+import net.minecraftforge.forge.tasks.checks.CheckTask
+import net.minecraftforge.forge.tasks.checks.CheckMode
 
 import java.nio.file.Files
 import java.util.Date
@@ -17,11 +24,12 @@ import org.gradle.plugins.ide.eclipse.model.SourceFolder
 plugins {
     id 'org.cadixdev.licenser' version '0.6.1'
     id 'com.github.ben-manes.versions' version '0.36.0'
-    id 'net.minecraftforge.gradleutils' version '2.+'
+    id 'net.minecraftforge.gradleutils' version '[2.2,2.3)'
     id 'eclipse'
-    id 'de.undercouch.download' version '4.1.2'
-    id 'net.minecraftforge.gradle.patcher' version '[5.1.39,)' apply false
-    id 'net.minecraftforge.gradle.mcp' version '[5.1.39,)' apply false
+    id 'idea'
+    id 'de.undercouch.download' version '5.1.3'
+    id 'net.minecraftforge.gradle.patcher' version '[6.0,6.2)' apply false
+    id 'net.minecraftforge.gradle.mcp' version '[6.0,6.2)' apply false
 }
 
 Util.init() //Init all our extension methods!
@@ -36,46 +44,32 @@ ext {
         ]
     }
     MAPPING_CHANNEL = 'official'
-    MAPPING_VERSION = '1.19'
-    MC_VERSION = '1.19'
-    MCP_VERSION = '20220607.102129'
-    SPI_VERSION = '4.0.10'
+    MAPPING_VERSION = '1.18.2'
+    MC_VERSION = '1.18.2'
+    MCP_VERSION = '20220404.173914'
+    SPI_VERSION = '4.0.15-4.x'
     ACCESSTRANSFORMERS_VERSION = '8.0.4'
-    COREMODS_VERSION = '5.0.1'
+    COREMODS_VERSION = '5.2.5'
     EVENTBUS_VERSION = '5.0.3'
     MODLAUNCHER_VERSION = '9.1.3'
-    SECUREJARHANDLER_VERSION = '1.0.3'
+    SECUREJARHANDLER_VERSION = '1.0.8'
     BOOTSTRAPLAUNCHER_VERSION = '1.0.0'
-    ASM_VERSION = '9.3'
-    INSTALLER_VERSION = '2.1.+'
+    ASM_VERSION = '9.7.1'
+    INSTALLER_VERSION = '2.2.+'
     MIXIN_VERSION = '0.8.5'
-    TERMINALCONSOLEAPPENDER_VERSION = '1.2.0'
-    JLINE_VERSION = '3.12.+'
-    NIGHTCONFIG_VERSION = '3.6.4'
-    JETBRAINS_ANNOTATIONS_VERSION = '23.0.0'
-    SLF4J_API_VERSION = '1.8.0-beta4'
-    APACHE_MAVEN_ARTIFACT_VERSION = '3.8.5'
-
-    // These versions should be kept in sync with the version manifest JSON
-    // To use a version newer than the version manifest JSON, the dependency must be added to the installer configuration
-    MOJANG_LOGGING_VERSION = '1.0.0'
-    LOG4J_VERSION = '2.17.0'
-    GUAVA_VERSION = '31.0.1-jre'
-    GSON_VERSION = '2.8.9'
-    APACHE_COMMONS_LANG3_VERSION = '3.12.0'
-    JOPT_SIMPLE_VERSION = '5.0.4'
-    COMMONS_IO_VERSION = '2.11.0'
+    JARJAR_VERSION = '0.3.19'
 
     GIT_INFO = gradleutils.gitInfo
     VERSION = gradleutils.getFilteredMCTagOffsetBranchVersion(true, '[0-9]', MC_VERSION)
     // FML_VERSION = gradleutils.getFilteredMCTagOffsetBranchVersion(true, 'FML', MC_VERSION)
     FORGE_VERSION = VERSION.substring(MC_VERSION.length() + 1)
 
-    BINPATCH_TOOL = 'net.minecraftforge:binarypatcher:1.1.1:fatjar'
-    INSTALLER_TOOLS = 'net.minecraftforge:installertools:1.3.0'
+    BINPATCH_TOOL = 'net.minecraftforge:binarypatcher:1.0.12:fatjar'
+    INSTALLER_TOOLS = 'net.minecraftforge:installertools:1.4.1'
     JAR_SPLITTER = 'net.minecraftforge:jarsplitter:1.1.4'
-    FART = 'net.minecraftforge:ForgeAutoRenamingTool:0.1.22:all'
+    FART = 'net.minecraftforge:ForgeAutoRenamingTool:0.1.25:all'
     MIN_TAG_FOR_CHANGELOG = "39.0"
+    LAST_RB = GIT_INFO.tag.rsplit('.', 1)[1] as int >= 1 ? GIT_INFO.tag + '.0' : null
 }
 
 println('Version: ' + VERSION +
@@ -208,46 +202,53 @@ project(':mcp') {
     }
 }
 
-project(':clean') {
-    evaluationDependsOn(':mcp')
-    apply plugin: 'net.minecraftforge.gradle.patcher'
-    tasks.withType(AbstractPublishToMaven.class).forEach{tsk -> tsk.enabled = false } // We don't want to publish anything
+if (!System.env.TEAMCITY_VERSION) {
+    project(':clean') {
+        evaluationDependsOn(':mcp')
+        apply plugin: 'net.minecraftforge.gradle.patcher'
+        tasks.withType(AbstractPublishToMaven.class).forEach{tsk -> tsk.enabled = false } // We don't want to publish anything
 
-    dependencies {
-        implementation 'net.minecraftforge:forgespi:' + SPI_VERSION
-    }
+        dependencies {
+            implementation 'net.minecraftforge:forgespi:' + SPI_VERSION
+        }
 
-    patcher {
-        parent = project(':mcp')
-        mcVersion = MC_VERSION
-        patchedSrc = file('src/main/java')
+        patcher {
+            parent = project(':mcp')
+            mcVersion = MC_VERSION
+            patchedSrc = file('src/main/java')
 
-        mappings channel: MAPPING_CHANNEL, version: MAPPING_VERSION
+            mappings channel: MAPPING_CHANNEL, version: MAPPING_VERSION
 
-        runs {
-            clean_client {
-                client true
-                taskName 'clean_client'
-                ideaModule "${rootProject.name}.${project.name}.main"
+            runs {
+                clean_client {
+                    client true
+                    taskName 'clean_client'
+                    ideaModule "${rootProject.name}.${project.name}.main"
 
-                main 'net.minecraft.client.main.Main'
-                workingDirectory project.file('run')
+                    main 'net.minecraft.client.main.Main'
+                    workingDirectory project.file('run')
 
-                args '--gameDir', '.'
-                args '--version', MC_VERSION
-                args '--assetsDir', downloadAssets.output
-                args '--assetIndex', '{asset_index}'
-                args '--accessToken', '0'
+                    args '--gameDir', '.'
+                    args '--version', MC_VERSION
+                    args '--assetsDir', downloadAssets.output
+                    args '--assetIndex', '{asset_index}'
+                    args '--accessToken', '0'
+                }
+
+                clean_server {
+                    client false
+                    taskName 'clean_server'
+                    ideaModule "${rootProject.name}.${project.name}.main"
+
+                    main 'net.minecraft.server.Main'
+                    workingDirectory project.file('run')
+                }
             }
+        }
 
-            clean_server {
-                client false
-                taskName 'clean_server'
-                ideaModule "${rootProject.name}.${project.name}.main"
-
-                main 'net.minecraft.server.Main'
-                workingDirectory project.file('run')
-            }
+        // Disabling clean with CI causes an error if we don't have this...
+        compileJava {
+            dependsOn 'extractMapped'
         }
     }
 }
@@ -260,6 +261,7 @@ def sharedDeps = {
     moduleonly "org.ow2.asm:asm-util:${ASM_VERSION}"
     moduleonly "org.ow2.asm:asm-analysis:${ASM_VERSION}"
     moduleonly "cpw.mods:bootstraplauncher:${BOOTSTRAPLAUNCHER_VERSION}"
+    moduleonly "net.minecraftforge:JarJarFileSystems:${JARJAR_VERSION}"
 
     installer "cpw.mods:securejarhandler:${SECUREJARHANDLER_VERSION}"
     installer "org.ow2.asm:asm:${ASM_VERSION}"
@@ -268,21 +270,25 @@ def sharedDeps = {
     installer "org.ow2.asm:asm-util:${ASM_VERSION}"
     installer "org.ow2.asm:asm-analysis:${ASM_VERSION}"
     installer "net.minecraftforge:accesstransformers:${ACCESSTRANSFORMERS_VERSION}"
-    installer 'org.antlr:antlr4-runtime:4.9.1' // Dep of AccessTransformer
+    installer 'org.antlr:antlr4-runtime:4.9.1' //Dep of AccessTransformer
     installer "net.minecraftforge:eventbus:${EVENTBUS_VERSION}"
     installer "net.minecraftforge:forgespi:${SPI_VERSION}"
-    installer "net.minecraftforge:coremods:${COREMODS_VERSION}"
+    installer("net.minecraftforge:coremods:${COREMODS_VERSION}")
     installer "cpw.mods:modlauncher:${MODLAUNCHER_VERSION}"
     installer 'net.minecraftforge:unsafe:0.2.+'
-    installer "com.electronwill.night-config:core:${NIGHTCONFIG_VERSION}"
-    installer "com.electronwill.night-config:toml:${NIGHTCONFIG_VERSION}"
-    installer "org.apache.maven:maven-artifact:${APACHE_MAVEN_ARTIFACT_VERSION}"
+    installer 'com.electronwill.night-config:core:3.6.4'
+    installer 'com.electronwill.night-config:toml:3.6.4'
+    installer 'org.apache.maven:maven-artifact:3.6.3'
     installer 'net.jodah:typetools:0.8.3'
-    installer "net.minecrell:terminalconsoleappender:${TERMINALCONSOLEAPPENDER_VERSION}"
-    installer "org.jline:jline-reader:${JLINE_VERSION}"   // Dep of TerminalConsoleAppender
-    installer "org.jline:jline-terminal:${JLINE_VERSION}" // Dep of TerminalConsoleAppender
+    installer 'net.minecrell:terminalconsoleappender:1.2.0'
+    installer 'org.jline:jline-reader:3.12.+'   //Dep of TerminaalConsoleeAppender
+    installer 'org.jline:jline-terminal:3.12.+' //Dep of TerminaalConsoleeAppender
     installer "org.spongepowered:mixin:${MIXIN_VERSION}"
-    installer 'org.openjdk.nashorn:nashorn-core:15.3'
+    installer 'org.openjdk.nashorn:nashorn-core:15.4'
+    installer "net.minecraftforge:JarJarSelector:${JARJAR_VERSION}"
+    installer "net.minecraftforge:JarJarMetadata:${JARJAR_VERSION}"
+    installer 'net.java.dev.jna:jna:5.12.1'
+    installer 'net.java.dev.jna:jna-platform:5.12.1'
 
     /*
     installer 'org.lwjgl:lwjgl:3.2.2'
@@ -333,7 +339,7 @@ def sharedFmlonlyForge = { Project prj ->
     }
 
     prj.task([type: DownloadMavenArtifact], 'downloadInstaller') {
-        artifact = "net.minecraftforge:installer:${INSTALLER_VERSION}:shrunk"
+        artifact = "net.minecraftforge:installer:${INSTALLER_VERSION}:fatjar"
         changing = true
     }
 
@@ -429,6 +435,8 @@ def sharedFmlonlyForge = { Project prj ->
         run.args '--fml.forgeGroup', prj.group
         run.args '--fml.mcpVersion', MCP_VERSION
 
+        run.jvmArgs '-Djava.net.preferIPv6Addresses=system'
+
         if (run.name.contains('client')) {
             run.client true
         } else {
@@ -438,7 +446,7 @@ def sharedFmlonlyForge = { Project prj ->
         // SecureJarHandler bootstrap values.
         run.property 'ignoreList', prj.configurations.moduleonly.files.collect {it.name.replaceAll(/([-_]([.\d]*\d+)|\.jar$)/, '') }.join(',') + ",client-extra,fmlcore,javafmllanguage,lowcodelanguage,mclanguage,${prj.name}-"
         // FIXME: Without this jna doesn't work at runtime. Someone figure out why please?
-        run.property 'mergeModules', 'jna-5.10.0.jar,jna-platform-5.10.0.jar,java-objc-bridge-1.0.0.jar'
+        run.property 'mergeModules', 'jna-5.12.1.jar,jna-platform-5.12.1.jar,java-objc-bridge-1.0.0.jar'
         if (userdevRuns.contains(run)) {
             run.property 'legacyClassPath.file', '{minecraft_classpath_file}'
             run.jvmArgs '-p', '{modules}'
@@ -449,6 +457,7 @@ def sharedFmlonlyForge = { Project prj ->
         run.jvmArgs '--add-modules', 'ALL-MODULE-PATH'
         // Additions to these JVM module args should be mirrored to server_files/args.txt and other similar blocks in the buildscript
         run.jvmArgs '--add-opens', 'java.base/java.util.jar=cpw.mods.securejarhandler'
+        run.jvmArgs '--add-opens', 'java.base/java.lang.invoke=cpw.mods.securejarhandler'
         run.jvmArgs '--add-exports', 'java.base/sun.security.util=cpw.mods.securejarhandler'
         run.jvmArgs '--add-exports', 'jdk.naming.dns/com.sun.jndi.dns=java.naming'
     }
@@ -639,6 +648,7 @@ project(':fmlonly') {
                           '--add-modules', 'ALL-MODULE-PATH',
                           // Additions to these JVM module args should be mirrored to server_files/args.txt and other similar blocks in the buildscript
                           '--add-opens', 'java.base/java.util.jar=cpw.mods.securejarhandler',
+                          '--add-opens', 'java.base/java.lang.invoke=cpw.mods.securejarhandler',
                           '--add-exports', 'java.base/sun.security.util=cpw.mods.securejarhandler',
                           '--add-exports', 'jdk.naming.dns/com.sun.jndi.dns=java.naming'
                     ]
@@ -858,10 +868,15 @@ project(':fmlonly') {
 
     // Since we need the modules in the bootstrap, we need to make sure they are compiled before we do each run
     afterEvaluate { prepareRuns.dependsOn(PACKED_DEPS) }
+
+    // Disabling clean with CI causes an error if we don't have this...
+    compileJava {
+        dependsOn 'extractMapped'
+    }
 }
 
 project(':forge') {
-    evaluationDependsOn(':clean')
+    evaluationDependsOn(System.env.TEAMCITY_VERSION ? ':mcp' : ':clean')
     apply plugin: 'java-library'
     apply plugin: 'net.minecraftforge.gradle.patcher'
     apply plugin: 'org.cadixdev.licenser'
@@ -935,13 +950,19 @@ project(':forge') {
 
     patcher {
         excs.from file("$rootDir/src/main/resources/forge.exc")
-        parent = project(':clean')
+        parent = project(System.env.TEAMCITY_VERSION ? ':mcp' : ':clean')
         patches = file("$rootDir/patches/minecraft")
         patchedSrc = file('src/main/java')
         srgPatches = true
         accessTransformers.from file("$rootDir/src/main/resources/META-INF/accesstransformer.cfg")
         sideAnnotationStrippers.from file("$rootDir/src/main/resources/forge.sas")
 
+        // the clean project provides these. if we're not using it, we need to provide them ourselves
+        if (System.env.TEAMCITY_VERSION) {
+            mappings channel: MAPPING_CHANNEL, version: MAPPING_VERSION
+            mcVersion = MC_VERSION
+        }
+
         runs {
             forge_client {
                 property 'eventbus.checkTypesOnDispatch', 'true'
@@ -1058,7 +1079,6 @@ project(':forge') {
                             '--mod', 'tag_based_tool_types',
                             '--mod', 'custom_transformtype_test',
                             '--mod', 'data_pack_registries_test',
-                            '--mod', 'biome_modifiers_test',
                             '--output', rootProject.file('src/generated_test/resources/'),
                             '--existing', sourceSets.main.resources.srcDirs[0],
                             '--existing', sourceSets.test.resources.srcDirs[0]
@@ -1118,9 +1138,12 @@ project(':forge') {
         ]
     }
 
-    task crowdin(type: Crowdin) {
-        key = project.hasProperty('crowdinKey') ? project.crowdinKey : null
-        //TODO: Merge our english.json?
+    tasks.register('downloadCrowdin', Download) {
+        src 'https://files.minecraftforge.net/crowdin.zip'
+        dest file('build/crowdin.zip')
+        useETag 'all'
+        onlyIfModified true
+        quiet true
     }
 
     sharedFmlonlyForge.call(project)
@@ -1156,89 +1179,98 @@ project(':forge') {
         }
     }
 
-    task checkATs(type: CheckATs, dependsOn: [extractInheritance, createSrg2Mcp]) {
-        inheritance = extractInheritance.output
+    tasks.register('checkAll') {
+        dependsOn 'checkLicenses'
+        group = 'checks'
+    }
+    tasks.register('checkAllAndFix') {
+        dependsOn 'findFieldInstanceChecks', 'checkLicenses'
+        group = 'checks'
+    }
+
+    CheckTask.registerTask(tasks, 'ATs', CheckATs) {
+        dependsOn extractInheritance, createSrg2Mcp
         ats.from patcher.accessTransformers
+        inheritance = extractInheritance.output
         mappings = createSrg2Mcp.output
     }
 
-    task checkSAS(type: CheckSAS, dependsOn: extractInheritance) {
-        inheritance = extractInheritance.output
+    CheckTask.registerTask(tasks, 'SAS', CheckSAS) {
+        dependsOn extractInheritance
         sass.from patcher.sideAnnotationStrippers
+        inheritance = extractInheritance.output
     }
 
-    task checkExcs(type: CheckExcs, dependsOn: jar) {
+    CheckTask.registerTask(tasks, 'Excs', CheckExcs) {
+        dependsOn jar
         binary = jar.archiveFile.get().asFile
         excs.from patcher.excs
     }
 
-    task checkAll(dependsOn: [checkATs, checkSAS, checkExcs, findFieldInstanceChecks]){}
-
-    task checkPatchesAndFix(type: CheckPatches, dependsOn: genPatches) {
+    CheckTask.registerTask(tasks, 'Patches', CheckPatches) {
+        dependsOn genPatches
         patchDir = file("$rootDir/patches")
-        autoFix = true
-    }
-
-    task checkPatches(type: CheckPatches, dependsOn: genPatches) {
-        patchDir = file("$rootDir/patches")
-        autoFix = false
+        patchesWithS2SArtifact = [
+                'minecraft/net/minecraft/client/renderer/ViewArea.java.patch',
+                'minecraft/net/minecraft/data/models/blockstates/Variant.java.patch',
+        ]
     }
 
     genPatches {
-        finalizedBy checkPatches
+        finalizedBy checkAndFixPatches
         autoHeader true
         lineEnding = '\n'
     }
 
-    def baseForgeVersion = System.getProperty("forge.compatibility_check_version")
-    if (baseForgeVersion == null)
-        baseForgeVersion = "${MC_VERSION}-${GIT_INFO.tag}.0"
-    if (baseForgeVersion == "null")
-        baseForgeVersion = null // Allow disabling from system property if not wanted
-    def baseForgeUniversal = null
-    if (baseForgeVersion != null)
-        baseForgeUniversal = project.dependencies.create("net.minecraftforge:forge:${baseForgeVersion}:universal")
+    def baseForgeVersionProperty = project.objects.property(String)
+    baseForgeVersionProperty.set(project.provider { TeamcityRequests.attemptFindBase(rootDir) ?: getLatestForgeVersion(MC_VERSION) })
+    baseForgeVersionProperty.finalizeValueOnRead()
     def jarCompatibilityTaskSetup = { task ->
         task.group = 'jar compatibility'
         task.onlyIf {
-            baseForgeVersion != null
+            baseForgeVersionProperty.getOrNull() != null
         }
-        task.inputs.property 'baseForgeVersion', baseForgeVersion
     }
 
-    task downloadBaseCompatibilityBinPatches(type: DownloadBaseCompatibilityBinPatches) {
-        inputVersion = baseForgeVersion
+    tasks.register('setupCheckJarCompatibility', SetupCheckJarCompatibility) {
+        inputVersion = baseForgeVersionProperty
     }
 
-    task applyBaseCompatibilityJarBinPatches(type: ApplyBinPatches) {
+    tasks.register('applyBaseCompatibilityJarBinPatches', ApplyBinPatches) {
         jarCompatibilityTaskSetup(it)
 
-        clean = createJoinedSRG.output
-        patch = downloadBaseCompatibilityBinPatches.output
+        clean = project.tasks.createJoinedSRG.output
+        patch = project.tasks.named('setupCheckJarCompatibility').flatMap { it.baseBinPatchesOutput }
         output = project.layout.buildDirectory.dir(name).map { it.file('output.jar') }
     }
 
-    task checkJarCompatibility(type: CheckJarCompatibility) {
+    tasks.register('mergeBaseForgeJar', MergeJars) {
         jarCompatibilityTaskSetup(it)
 
-        if (baseForgeVersion != null) {
-            def fmlLibs = project.configurations.detachedConfiguration(PACKED_DEPS.collect {
-                def artifactId = it.split(':')[1]
-                return project.dependencies.create("net.minecraftforge:${artifactId}:${baseForgeVersion}")
-            }.toArray(Dependency[]::new))
+        inputJars.from(project.tasks.named('applyBaseCompatibilityJarBinPatches').flatMap { it.output })
+        inputJars.from(baseForgeVersionProperty.map { inputVersion ->
+            def output = project.layout.buildDirectory.dir(name).map { it.file("forge-${inputVersion}-universal.jar") }.get().asFile
+            project.rootProject.extensions.download.run {
+                src "https://maven.minecraftforge.net/net/minecraftforge/forge/${inputVersion}/forge-${inputVersion}-universal.jar"
+                dest output
+            }
+            return output
+        })
+    }
 
-            baseJar = project.tasks.applyBaseCompatibilityJarBinPatches.output
-            baseLibraries.from(baseForgeUniversal)
-            baseLibraries.from(project.tasks.createJoinedSRG.output)
-            baseLibraries.from(fmlLibs)
+    tasks.register('checkJarCompatibility', CheckJarCompatibility) {
+        jarCompatibilityTaskSetup(it)
+        dependsOn 'setupCheckJarCompatibility'
 
-            inputJar = project.tasks.reobfJar.output
-            concreteLibraries.from(PACKED_DEPS.collect { rootProject.tasks.getByPath(it).archiveFile })
+        baseJar = project.tasks.named('mergeBaseForgeJar').flatMap { it.output }
+        baseLibraries.from(project.tasks.named('createJoinedSRG').flatMap { it.output })
 
-            commonLibraries.from(project.configurations.minecraftImplementation)
-            commonLibraries.from(project.configurations.installer)
-            commonLibraries.from(project.configurations.moduleonly)
-        }
+        inputJar = project.tasks.named('reobfJar').flatMap { it.output }
+        concreteLibraries.from(project.PACKED_DEPS.collect { project.rootProject.tasks.getByPath(it).archiveFile })
+
+        commonLibraries.from(project.configurations.minecraftImplementation)
+        commonLibraries.from(project.configurations.installer)
+        commonLibraries.from(project.configurations.moduleonly)
     }
 
     task launcherJson(type: LauncherJson) {
@@ -1260,13 +1292,15 @@ project(':forge') {
                            '--fml.mcVersion', MC_VERSION,
                            '--fml.forgeGroup', project.group,
                            '--fml.mcpVersion', MCP_VERSION],
-                    jvm: ["-DignoreList=${forge_client.properties.ignoreList},\${version_name}.jar",
+                    jvm: ['-Djava.net.preferIPv6Addresses=system',
+                          "-DignoreList=${forge_client.properties.ignoreList},\${version_name}.jar",
                           "-DmergeModules=${forge_client.properties.mergeModules}",
                           '-DlibraryDirectory=${library_directory}',
                           '-p', Util.getArtifacts(project, configurations.moduleonly, false).values().collect{'${library_directory}/' + it.downloads.artifact.path}.join('${classpath_separator}'),
                           '--add-modules', 'ALL-MODULE-PATH',
                           // Additions to these JVM module args should be mirrored to server_files/args.txt and other similar blocks in the buildscript
                           '--add-opens', 'java.base/java.util.jar=cpw.mods.securejarhandler',
+                          '--add-opens', 'java.base/java.lang.invoke=cpw.mods.securejarhandler',
                           '--add-exports', 'java.base/sun.security.util=cpw.mods.securejarhandler',
                           '--add-exports', 'jdk.naming.dns/com.sun.jndi.dns=java.naming'
                     ]
@@ -1496,9 +1530,12 @@ project(':forge') {
         from extraTxts
 
         // add crowdin locales
-        from { crowdin.output.present && crowdin.output.get().asFile.exists() ? zipTree(crowdin.output) : null}
-        dependsOn crowdin
-        duplicatesStrategy = 'exclude'
+        from zipTree(downloadCrowdin.dest).matching {
+            include 'assets/forge/lang/*.json'
+        }
+
+        dependsOn downloadCrowdin
+        duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 
         doFirst {
             MANIFESTS.each{ pkg, values ->
@@ -1543,7 +1580,7 @@ project(':forge') {
                     exclude it
             }
             filter(ReplaceTokens, tokens: [
-                FORGE_VERSION: project.version,
+                FORGE_VERSION: FORGE_VERSION,
                 FORGE_GROUP: project.group,
                 FORGE_NAME: project.name,
                 MC_VERSION: MC_VERSION,
@@ -1591,83 +1628,6 @@ project(':forge') {
         sourceSets.test.java.srcDirs.each { extractMappedNew.addTarget it }
     }
 
-    tasks.named('javadoc', Javadoc).configure {
-        description 'Generates the combined javadocs for the FML projects and the main Forge project'
-        var includedProjects = [ ':fmlcore', ':fmlloader', ':javafmllanguage', ':mclanguage' ]
-        source includedProjects.collect { project(it).sourceSets.main.allJava }
-        classpath = classpath + files(includedProjects.collect { project(it).sourceSets.main.compileClasspath })
-
-        var docsDir = rootProject.file('src/docs/')
-        inputs.dir(docsDir)
-            .withPropertyName('docs resources directory')
-            .withPathSensitivity(PathSensitivity.RELATIVE)
-            .optional()
-
-        failOnError = false
-
-        // Exclude the Minecraft classes if not enabled
-        if (!project.hasProperty('generateAllDocumentation')) {
-            exclude 'net/minecraft/**'
-            exclude 'com/mojang/**'
-        }
-        exclude 'mcp/**'
-
-        options.addStringOption('Xdoclint:all,-missing', '-public')
-        options {
-            stylesheetFile = new File(docsDir, 'stylesheet.css')
-
-            tags = [
-                'apiNote:a:<em>API Note:</em>',
-                'implSpec:a:<em>Implementation Requirements:</em>',
-                'implNote:a:<em>Implementation Note:</em>'
-            ]
-
-            groups = [
-                'Forge Mod Loader': [
-                    'net.minecraftforge.fml.common.asm*',
-                    'net.minecraftforge.fml.loading*',
-                    'net.minecraftforge.fml.server*'
-                ],
-                'FML Core':  [
-                    'net.minecraftforge.fml',
-                    'net.minecraftforge.fml.config*',
-                    'net.minecraftforge.fml.event*',
-                    'net.minecraftforge.fml.util*'
-                ],
-                'FML Common': [
-                    'net.minecraftforge.fml.core',
-                    'net.minecraftforge.fml.event.config',
-                    'net.minecraftforge.fml.event.lifecycle'
-                ],
-                'FML Java/MC Language Providers': [
-                    'net.minecraftforge.fml.common',
-                    'net.minecraftforge.fml.javafmlmod',
-                    'net.minecraftforge.fml.mclanguageprovider'
-                ],
-                'Minecraft Forge API': [
-                    'net.minecraftforge*'
-                ]
-            ]
-
-            author = false
-            noSince = true
-            noHelp = true
-
-            bottom = "Minecraft Forge is an open source modding API for Minecraft: Java Edition, licensed under the Lesser GNU General Public License, version 2.1."
-            windowTitle = "Minecraft Forge API ${VERSION}"
-            docTitle = "Minecraft Forge API - ${FORGE_VERSION} for Minecraft ${MC_VERSION}"
-            header = "<div style=\"margin-top: 9px;padding: 5px 6px;\"><strong>${FORGE_VERSION} for Minecraft ${MC_VERSION}</strong></div>"
-        }
-
-        doLast {
-            project.copy {
-                from docsDir
-                exclude '/stylesheet.css'
-                into destinationDir
-            }
-        }
-    }
-
     publishing {
         publications {
             mavenJava(MavenPublication) {
@@ -1686,11 +1646,17 @@ project(':forge') {
     tasks.withType(JavaCompile).configureEach {
         options.encoding = 'UTF-8' // Use the UTF-8 charset for Java compilation
     }
+
+    // Disabling clean with CI causes an error if we don't have this...
+    compileJava {
+        dependsOn 'extractMapped'
+    }
 }
 
 //evaluationDependsOnChildren()
 task setup() {  //These must be strings so that we can do lazy resolution. Else we need evaluationDependsOnChildren above
-    dependsOn ':clean:extractMapped'
+    if (!System.env.TEAMCITY_VERSION)
+        dependsOn ':clean:extractMapped'
     if (symlinkValid)
         dependsOn ':fmlonly:extractMapped'
     dependsOn ':forge:extractMapped'
@@ -1706,4 +1672,12 @@ if (System.env.TEAMCITY_VERSION) {
             println "##teamcity[setParameter name='env.PUBLISHED_JAVA_FML_ARTIFACT_VERSION' value='${project(':fmlonly').version}']"
         }
     }
+}
+
+idea {
+    module {
+        // IntelliJ IDEA does not do this by itself anymore...
+        downloadJavadoc = true
+        downloadSources = true
+    }
 }

buildSrc/build.gradle

@@ -1,10 +1,12 @@
 repositories {
     maven { url = 'https://maven.minecraftforge.net/' }
-	mavenCentral()
+    mavenCentral()
 }
-
 dependencies {
-	implementation 'org.ow2.asm:asm:9.3'
-	implementation 'org.ow2.asm:asm-tree:9.3'
-    implementation 'net.minecraftforge:srgutils:0.4.+'
+    implementation 'org.ow2.asm:asm:9.5'
+    implementation 'org.ow2.asm:asm-tree:9.5'
+    implementation 'net.minecraftforge:srgutils:0.5.+'
+    implementation 'commons-io:commons-io:2.8.0'
+    implementation 'com.google.code.gson:gson:2.10'
+    implementation 'org.eclipse.jgit:org.eclipse.jgit:6.5.0.202303070854-r'
 }

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckATs.groovy

@@ -1,267 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import net.minecraftforge.srgutils.IMappingFile
-import org.gradle.api.file.ConfigurableFileCollection
-import org.gradle.api.file.RegularFileProperty
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.Optional
-import org.gradle.api.tasks.TaskAction
-import org.objectweb.asm.Opcodes
-
-abstract class CheckATs extends DefaultTask {
-	@InputFile abstract RegularFileProperty getInheritance()
-	@InputFiles abstract ConfigurableFileCollection getAts()
-    @InputFile @Optional abstract RegularFileProperty getMappings()
-	
-    @TaskAction
-    protected void exec() {
-        def mappings = mappings.map { IMappingFile.load(it.asFile) }.getOrNull()
-		Util.init()
-		def parse = { line ->
-			def idx = line.indexOf('#')
-			def comment = idx == -1 ? null : line.substring(idx)
-			if (idx != -1) line = line.substring(0, idx - 1)
-			def (modifier, cls, desc) = (line.trim() + '     ').split(' ', -1)
-			def key = cls + (desc.isEmpty() ? '' : ' ' + desc)
-			return [modifier, cls, desc, comment, key]
-		}
-		def accessLevel = { access ->
-			if ((access & Opcodes.ACC_PUBLIC)    != 0) return 3
-			if ((access & Opcodes.ACC_PROTECTED) != 0) return 2
-			if ((access & Opcodes.ACC_PRIVATE)   != 0) return 0
-			return 1
-		}
-		def accessStr = { access ->
-			if (access.endsWith('-f') || access.endsWith('+f'))
-				return 4
-			switch (access.toLowerCase()) {
-				case 'public':    return 3
-				case 'protected': return 2
-				case 'default':   return 1
-				case 'private':   return 0
-				default:          return -1
-			}
-		}
-		def json = inheritance.get().asFile.json()
-		
-		ats.each { f -> 
-			TreeMap lines = [:]
-			def group = null
-			for (def line : f.readLines()) {
-				if (line.isEmpty()) continue
-				if (line.startsWith('#group ')) {
-					def (modifier, cls, desc, comment, key) = parse.call(line.substring(7))
-					
-					if (desc != '*' && desc != '*()' && desc != '<init>')
-						throw new IllegalStateException('Invalid group: ' + line)
-					
-					group = [modifier: modifier, cls: cls, desc: desc, comment: comment, 
-						existing: [] as Set,
-						children: [] as TreeSet,
-						group: true
-					]
-					if (lines.containsKey(key))
-						throw new IllegalStateException('Duplicate group: ' + line)
-					
-					lines[key] = group
-				} else if (group != null) {
-					if (line.startsWith('#endgroup')) {
-						group = null
-					} else {
-						def (modifier, cls, desc, comment, key) = parse.call(line)
-						group['existing'].add(key)
-					}
-				} else if (line.startsWith('#endgroup')) {
-					throw new IllegalStateException('Invalid group ending: ' + line)
-				} else if (line.startsWith('#')) {
-					//Nom
-				} else {
-					def (modifier, cls, desc, comment, key) = parse.call(line)
-					if (lines.containsKey(key)) {
-						println('Duplicate: ' + line)
-						continue
-					}
-					lines[key] = [modifier: modifier, cls: cls, desc: desc, comment: comment, group: false]
-				}
-			}
-			
-			// Process Groups, this will remove any entries outside the group that is covered by the group
-			for (def key : new ArrayList<>(lines.keySet())) {
-				def entry = lines.get(key)
-				if (entry != null && entry['group']) {
-					def cls = entry['cls']
-					def jcls = json.get(cls.replaceAll('\\.', '/'))
-					if (jcls == null) {
-						lines.remove(key)
-						println('Invalid Group: ' + key)
-					} else if ('*' == entry['desc']) {
-						if (!jcls.containsKey('fields')) {
-							lines.remove(key)
-							println('Invalid Group, Class has no fields: ' + key)
-						} else {
-							jcls['fields'].each { field, value ->
-								def fkey = cls + ' ' + field
-								if (accessLevel.call(value['access']) < accessStr.call(entry['modifier'])) {
-									if (lines.containsKey(fkey)) {
-										lines.remove(fkey)
-									} else if (!entry['existing'].contains(fkey)) {
-										println('Added: ' + fkey)
-									}
-									entry['children'].add(fkey)
-								} else if (lines.containsKey(fkey)) {
-									lines.remove(fkey)
-									println('Removed: ' + fkey)
-								}
-							}
-							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
-						}
-					} else if ('*()' == entry['desc']) {
-						if (!jcls.containsKey('methods')) {
-							lines.remove(key)
-							println('Invalid Group, Class has no methods: ' + key)
-						} else {
-							jcls['methods'].each{ mtd, value ->
-								if (mtd.startsWith('<clinit>') || mtd.startsWith('lambda$'))
-									return
-								key = cls + ' ' + mtd.replace(' ', '')
-								if (accessLevel.call(value['access']) < accessStr.call(entry['modifier'])) {
-									if (lines.containsKey(key)) {
-										lines.remove(key)
-									} else if (!entry['existing'].contains(key)) {
-										println('Added: ' + key)
-									}
-									entry['children'].add(key)
-								} else if (lines.containsKey(key)) {
-									lines.remove(key)
-									println('Removed: ' + key)
-								}
-							}
-							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
-						}
-					} else if ('<init>' == entry['desc']) { //Make all public non-abstract subclasses
-						json.each{ tcls,value -> 
-							if (!value.containsKey('methods') || ((value['access'] & Opcodes.ACC_ABSTRACT) != 0))
-								return
-							def parents = [] as Set
-							def parent = tcls
-							while (parent != null && json.containsKey(parent)) {
-								parents.add(parent)
-								def p = json[parent]
-								parent = p == null ? null : p['superName']
-							}
-							if (parents.contains(cls.replaceAll('\\.', '/'))) {
-								value['methods'].each{ mtd, v -> 
-									if (mtd.startsWith('<init>')) {
-										def child = tcls.replaceAll('/', '\\.') + ' ' + mtd.replace(' ', '')
-										if (accessLevel.call(v['access']) < 3) {
-											if (lines.containsKey(child)) {
-												lines.remove(child)
-											} else if (!entry['existing'].contains(child)) {
-												println('Added: ' + child)
-											}
-											entry['children'].add(child)
-										} else if (lines.containsKey(child)) {
-											lines.remove(child)
-											println('Removed: ' + child)
-										}
-									}
-								}
-							}
-						}
-						entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
-					}
-				}
-			}
-			
-			// Process normal lines, remove invalid and remove narrowing
-			for (def key : new ArrayList<>(lines.keySet())) {
-				def entry = lines.get(key)
-				if (entry != null && !entry['group']) {
-					def cls = entry['cls']
-					def jcls = json.get(cls.replaceAll('\\.', '/'))
-					if (jcls == null) {
-						lines.remove(key)
-						println('Invalid: ' + key)
-					} else if (entry['desc'] == '') {
-						if (accessLevel.call(jcls['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
-							lines.remove(key)
-							println('Invalid Narrowing: ' + key)
-						}
-					} else if (!entry['desc'].contains('(')) {
-						if (!jcls.containsKey('fields') || !jcls['fields'].containsKey(entry['desc'])) {
-							lines.remove(key)
-							println('Invalid: ' + key)
-						} else {
-							def value = jcls['fields'][entry['desc']]
-							if (accessLevel.call(value['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
-								lines.remove(key)
-								println('Invalid Narrowing: ' + key)
-								println(entry.comment)
-							}
-						}
-					} else {
-						def jdesc = entry['desc'].replace('(', ' (')
-						if (!jcls.containsKey('methods') || !jcls['methods'].containsKey(jdesc)) {
-							lines.remove(key)
-							println('Invalid: ' + key)
-						} else {
-							def value = jcls['methods'][jdesc]
-							if (accessLevel.call(value['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
-								lines.remove(key)
-								println('Invalid Narrowing: ' + key)
-							}
-						}
-					}
-				}
-			}
-
-			
-			def data = []
-            def remapComment = { entry ->
-                if (!mappings || !entry || !entry.desc) return null
-                def comment = entry.comment?.substring(1)?.trim()
-                def jsonCls = json.get(entry.cls.replaceAll('\\.', '/'))
-                def mappingsClass = mappings?.getClass(jsonCls.name)
-                if (!mappingsClass) return entry.comment
-                def idx = entry.desc.indexOf('(')
-                def mappedName = idx == -1
-                        ? mappingsClass.remapField(entry.desc)
-                        : mappingsClass.remapMethod(entry.desc.substring(0, idx), entry.desc.substring(idx))
-                if (!mappedName) return entry.comment
-                if (mappedName == '<init>')
-                    mappedName = 'constructor'
-
-                if (comment?.startsWith(mappedName))
-                    return '# ' + comment
-                if (comment && comment.indexOf(' ') != -1) {
-                    def split = comment.split(" - ").toList()
-                    if (split[0].indexOf(' ') != -1)
-                        // The first string is more than one word, so append before it
-                        return "# ${mappedName} - ${comment}"
-                    split.remove(0)
-                    return "# ${mappedName} - ${String.join(' - ', split)}"
-                }
-                return '# ' + mappedName
-            }
-			lines.each { key,value -> 
-				if (!value.group) {
-                    def comment = remapComment.call(value)
-					data.add(value.modifier + ' ' + key + (comment ? ' ' + comment : ''))
-				} else {
-					data.add('#group ' + value.modifier + ' ' + key + (value.comment == null ? '' : ' ' + value.comment))
-					value.children.each {
-                        def line = value.modifier + ' ' + it
-                        def (modifier, cls, desc, comment) = parse.call(line)
-                        comment = remapComment.call([modifier: modifier, cls: cls, desc: desc, comment: comment])
-                        data.add(line + (comment ? ' ' + comment : ''))
-                    }
-					data.add('#endgroup')
-				}
-			}
-			f.text = data.join('\n')
-		}
-	}
-}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckExcs.groovy

@@ -1,94 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import org.gradle.api.file.ConfigurableFileCollection
-import org.gradle.api.file.RegularFileProperty
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.TaskAction
-
-import org.objectweb.asm.ClassReader
-import org.objectweb.asm.ClassVisitor
-import org.objectweb.asm.MethodVisitor
-import org.objectweb.asm.Opcodes
-import org.objectweb.asm.Type
-
-import java.util.zip.ZipEntry
-import java.util.zip.ZipInputStream
-
-abstract class CheckExcs extends DefaultTask {
-	@InputFile abstract RegularFileProperty getBinary()
-	@InputFiles abstract ConfigurableFileCollection getExcs()
-	
-    @TaskAction
-    protected void exec() {
-		Util.init()
-		def known = []
-		binary.get().asFile.withInputStream { i ->
-			new ZipInputStream(i).withCloseable { zin ->
-				def visitor = new ClassVisitor(Opcodes.ASM9) {
-					private String cls
-					@Override
-					public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
-						this.cls = name
-					}
-					
-					@Override
-					public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
-						known.add(this.cls + '.' + name + descriptor)
-						super.visitMethod(access, name, descriptor, signature, exceptions)
-					}
-				}
-				ZipEntry zein
-				while ((zein = zin.nextEntry) != null) {
-					if (zein.name.endsWith('.class')) {
-						ClassReader reader = new ClassReader(zin)
-						reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES)
-					}
-				}
-			}
-		}
-		
-		excs.each { f -> 
-			def lines = []
-			f.eachLine { line ->
-				def idx = line.indexOf('#')
-				if (idx == 0 || line.isEmpty()) {
-					return
-				}
-				
-				def comment = idx == -1 ? null : line.substring(idx)
-				if (idx != -1) line = line.substring(0, idx - 1)
-				
-				if (!line.contains('=')) {
-					println('Invalid: ' + line)
-					return
-				}
-				
-				def (key, value) = line.split('=', 2)
-				if (!known.contains(key)) {
-					println('Unknown: ' + line)
-					return
-				}
-				
-				def (cls, desc) = key.split('\\.', 2)
-				if (!desc.contains('(')) {
-					println('Invalid: ' + line)
-					return
-				}
-				def name = desc.split('\\(', 2)[0]
-				desc = '(' + desc.split('\\(', 2)[1]
-				
-				def (exceptions, args) = value.contains('|') ? value.split('|', 2) : [value, '']
-				
-				if (args.split(',').length != Type.getArgumentTypes(desc).length) {
-					println('Invalid: ' + line)
-					return
-				}
-				lines.add(line)
-			}
-			f.text = lines.sort().join('\n')
-		}
-	}
-}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckPatches.groovy

@@ -1,219 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.file.DirectoryProperty
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.InputDirectory
-import org.gradle.api.tasks.TaskAction
-
-import java.nio.file.Files
-import java.nio.file.Paths
-import java.util.regex.Pattern
-
-abstract class CheckPatches extends DefaultTask {
-    @InputDirectory abstract DirectoryProperty getPatchDir()
-    @Input boolean autoFix = false
-
-    @TaskAction
-    protected void exec() {
-        def hasS2SArtifact = [
-                Paths.get("patches/minecraft/net/minecraft/client/renderer/ViewArea.java.patch"),
-                Paths.get("patches/minecraft/net/minecraft/data/models/blockstates/Variant.java.patch")
-        ]
-
-        def verified = true;
-        patchDir.get().asFileTree.each { patch ->
-            def patchPath = project.rootDir.toPath().relativize(patch.toPath())
-            verified &= verifyPatch(patch, autoFix, patchPath.toString(), hasS2SArtifact.contains(patchPath))
-        }
-
-        if (!verified)
-            throw new RuntimeException('One or more patches failed verification. Check the log for errors.')
-    }
-
-    def verifyPatch(patch, fix, patchPath, hasS2SArtifact) {
-        def hunk_start_pattern = Pattern.compile('^@@ -[0-9,]* \\+[0-9,_]* @@$')
-        def white_space_pattern = Pattern.compile('^[+\\-]\\s*$')
-        def import_pattern = Pattern.compile('^[+\\-]\\s*import.*')
-        def field_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^=;]*)(=.*)?;\\s*$')
-        def method_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^(]*)[(]([^)]*)?[)]\\s*[{]\\s*$')
-        def class_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final[\\s]*)?(class|interface)([^{]*)[{]\\s*$')
-
-        def accessMap = [("private"):0, (null):1, ("protected"):2, ("public"):3]
-
-        def hasProblem = false;
-        def lines = patch.readLines()
-
-        def hunksStart = 0
-        def onlyWhiteSpace = false
-
-        def didFix = false
-        def newLines = []
-        def whiteSpaceErrors = []
-
-        // First two lines are file name ++/-- and we do not care
-        newLines.add(lines[0] + '\n')
-        newLines.add(lines[1] + '\n')
-
-        int i = 2
-        for (; i < lines.size(); ++i) {
-            def line = lines[i]
-            newLines.add(line + '\n')
-
-            if (hunk_start_pattern.matcher(line).find()) {
-                if (onlyWhiteSpace) {
-                    if (fix || hasS2SArtifact) {
-                        logger.lifecycle("Removing white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
-                        def toRemove = i - hunksStart;
-                        while (toRemove-- > 0)
-                            newLines.remove(newLines.size() - 1)
-                        didFix = true
-                    }
-                    else {
-                        logger.lifecycle("Patch contains only white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
-                        hasProblem = true
-                    }
-                }
-                else {
-                    if (!whiteSpaceErrors.empty)
-                        hasProblem = true
-                    whiteSpaceErrors.each { error -> logger.lifecycle(error) }
-                    whiteSpaceErrors.clear()
-                }
-                hunksStart = i
-                onlyWhiteSpace = true
-                continue
-            }
-
-            if (line.startsWithAny('+','-')) {
-                def prefixChange = false
-                def prevLine = lines[i - 1]
-
-                if (line.charAt(0) == (char)'+' && prevLine.charAt(0) == (char)'-') {
-                    def prevTrim = prevLine.substring(1).replaceAll("\\s", "")
-                    def currTrim = line.substring(1).replaceAll("\\s", "")
-
-                    if (prevTrim.equals(currTrim)) {
-                        prefixChange = true
-                    }
-
-                    def pMatcher = field_pattern.matcher(prevLine)
-                    def cMatcher = field_pattern.matcher(line)
-
-                    if (pMatcher.find() && cMatcher.find() &&
-                            pMatcher.group(6) == cMatcher.group(6) && // = ...
-                            pMatcher.group(5) == cMatcher.group(5) && // field name
-                            pMatcher.group(3) == cMatcher.group(3) && // static
-                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
-                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
-                        hasProblem = true
-                    }
-
-                    pMatcher = method_pattern.matcher(prevLine)
-                    cMatcher = method_pattern.matcher(line)
-
-                    if (pMatcher.find() && cMatcher.find() &&
-                            pMatcher.group(6) == cMatcher.group(6) && // params
-                            pMatcher.group(5) == cMatcher.group(5) && // <T> void name
-                            pMatcher.group(3) == cMatcher.group(3) && // static
-                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
-                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
-                        hasProblem = true
-                    }
-
-                    pMatcher = class_pattern.matcher(prevLine)
-                    cMatcher = class_pattern.matcher(line)
-
-                    if (pMatcher.find() && cMatcher.find() &&
-                            pMatcher.group(6) == cMatcher.group(6) && // ClassName<> extends ...
-                            pMatcher.group(5) == cMatcher.group(5) && // class | interface
-                            pMatcher.group(3) == cMatcher.group(3) && // static
-                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
-                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
-                        hasProblem = true
-                    }
-                }
-
-                if (line.charAt(0) == (char)'-' && i + 1 < lines.size()) {
-                    def nextLine = lines[i + 1]
-                    if (nextLine.charAt(0) == (char)'+') {
-                        def nextTrim = nextLine.substring(1).replaceAll("\\s", "")
-                        def currTrim = line.substring(1).replaceAll("\\s", "")
-
-                        if (nextTrim.equals(currTrim)) {
-                            prefixChange = true
-                        }
-                    }
-                }
-
-                def isWhiteSpaceChange = white_space_pattern.matcher(line).find()
-
-                if (!prefixChange && !isWhiteSpaceChange) {
-                    onlyWhiteSpace = hasS2SArtifact && import_pattern.matcher(line).find()
-                }
-                else if (isWhiteSpaceChange) {
-                    def prevLineChange = prevLine.startsWithAny('+','-')
-                    def nextLineChange = i + 1 < lines.size() && lines[i + 1].startsWithAny('+','-')
-
-                    if (!prevLineChange && !nextLineChange) {
-                        whiteSpaceErrors.add(String.format("Patch contains white space change in valid hunk at line %d (cannot auto fix), file: %s", i + 1, patchPath))
-                    }
-                }
-
-                if (line.contains("\t")) {
-                    if (!fix) {
-                        logger.lifecycle("Patch contains tabs on line {}, file: {}", i + 1, patchPath)
-                        hasProblem = true
-                    }
-                    else {
-                        logger.lifecycle("Fixing tabs on line {}, file: {}", i + 1, patchPath)
-                        line = line.replaceAll('\t', '    ')
-                        newLines.remove(newLines.size() - 1)
-                        newLines.add(line + '\n')
-                        didFix = true
-                    }
-                }
-
-                if (import_pattern.matcher(line).find() && !hasS2SArtifact) {
-                    logger.lifecycle("Patch contains import change on line {}, file: {}", i + 1, patchPath)
-                    hasProblem = true
-                }
-            }
-        }
-
-        if (onlyWhiteSpace) {
-            if (fix || hasS2SArtifact) {
-                logger.lifecycle("Removing white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
-                def toRemove = i - hunksStart;
-                while (toRemove-- > 0)
-                    newLines.remove(newLines.size() - 1)
-                didFix = true
-            }
-            else {
-                logger.lifecycle("Patch contains only white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
-                hasProblem = true
-            }
-        }
-        else {
-            if (!whiteSpaceErrors.empty)
-                hasProblem = true
-            whiteSpaceErrors.each { error -> logger.lifecycle(error) }
-        }
-
-        if (didFix) {
-            if (newLines.size() <= 2) {
-                logger.lifecycle("Patch is now empty removing, file: {}", patchPath)
-                Files.delete(patch.toPath())
-            }
-            else {
-                if (!hasS2SArtifact)
-                    logger.lifecycle("*** Updating patch file. Please run setup then genPatches again. ***")
-                patch.withWriter('UTF-8') { writer ->
-                    newLines.each { l -> writer.write(l) }
-                }
-            }
-        }
-
-        return !hasProblem
-    }
-}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckSAS.groovy

@@ -1,107 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import org.gradle.api.file.ConfigurableFileCollection
-import org.gradle.api.file.RegularFileProperty
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.TaskAction
-
-abstract class CheckSAS extends DefaultTask {
-	@InputFile abstract RegularFileProperty getInheritance()
-	@InputFiles abstract ConfigurableFileCollection getSass()
-	
-    @TaskAction
-    protected void exec() {
-		Util.init()
-		def json = inheritance.get().asFile.json()
-		
-		sass.each { f -> 
-			def lines = []
-			f.eachLine { line ->
-				if (line[0] == '\t') return //Skip any tabbed lines, those are ones we add
-				def idx = line.indexOf('#')
-				if (idx == 0 || line.isEmpty()) {
-					lines.add(line)
-					return
-				}
-				def comment = idx == -1 ? null : line.substring(idx)
-				if (idx != -1) line = line.substring(0, idx - 1)
-				def (cls, name, desc) = (line.trim().replace('(', ' (') + '     ').split(' ', -1)
-				cls = cls.replaceAll('\\.', '/')
-
-				if (json[cls] == null) {
-					println('Invalid: ' + line)
-				} else if (name.isEmpty()) { //Class SAS
-                    def toAdd = []
-                    def clsSided = isSided(json[cls])
-                    def sided = clsSided
-                    
-                    /* TODO: MergeTool doesn't do fields
-                    if (json[cls]['fields'] != null) {
-						for (entry in json[cls]['fields']) {
-                            if (isSided(entry.value)) {
-                                sided = true
-                                toAdd.add('\t' + cls + ' ' + entry.key)
-                            }
-						}
-                    }
-                    */
-					if (json[cls]['methods'] != null) {
-                        for (entry in json[cls]['methods']) {
-                            if (isSided(entry.value)) {
-                                sided = true
-                                toAdd.add('\t' + cls + ' ' + entry.key.replaceAll(' ', ''))
-                                findChildMethods(json, cls, entry.key).each { lines.add('\t' + it) }
-                                findChildMethods(json, cls, entry.key).each { println(line + ' -- ' + it) }
-                            } else if (clsSided) {
-                                findChildMethods(json, cls, entry.key).each { lines.add('\t' + it) }
-                                findChildMethods(json, cls, entry.key).each { println(line + ' -- ' + it) }
-                            }
-						}
-                    }
-                    
-                    if (sided) {
-                        lines.add(cls + (comment == null ? '' : ' ' + comment))
-                        lines.addAll(toAdd.sort())
-                    } else
-                        println('Invalid: ' + line)
-                    
-                } else if (desc.isEmpty()) { // Fields
-                    /* TODO: MergeTool doesn't do fields
-                    if (json[cls]['fields'] != null && isSided(json[cls]['fields'][name]))
-                        lines.add(cls + ' ' + name + (comment == null ? '' : ' ' + comment))
-                    else
-                    */
-                        println('Invalid: ' + line)
-                } else { // Methods
-                    if (json[cls]['methods'] == null || !isSided(json[cls]['methods'][name + ' ' + desc]))
-                        println('Invalid: ' + line)
-                    else {
-                        lines.add(cls + ' ' + name + desc + (comment == null ? '' : ' ' + comment))
-                        findChildMethods(json, cls, name + ' ' + desc).each { println(line + ' -- ' + it) }
-                        findChildMethods(json, cls, name + ' ' + desc).each { lines.add('\t' + it) }
-                    }
-                }
-			}
-			f.text = lines.join('\n')
-		}
-	}
-
-    protected static isSided(json) {
-        if (json == null || json['annotations'] == null)
-            return false
-        for (ann in json['annotations']) {
-            if ('Lnet/minecraftforge/api/distmarker/OnlyIn;'.equals(ann.desc))
-                return true
-        }
-        return false
-    }
-    
-	protected static findChildMethods(json, cls, desc)
-	{
-		return json.values().findAll{ it.methods != null && it.methods[desc] != null && it.methods[desc].override == cls && isSided(it.methods[desc]) }
-				.collect { it.name + ' ' + desc.replace(' ', '') } as TreeSet
-	}
-}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/DownloadBaseCompatibilityBinPatches.groovy

@@ -1,39 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.file.RegularFileProperty
-import org.gradle.api.provider.Property
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.Optional
-import org.gradle.api.tasks.OutputFile
-import org.gradle.api.tasks.TaskAction
-
-import java.nio.file.Files
-
-abstract class DownloadBaseCompatibilityBinPatches extends DefaultTask {
-    DownloadBaseCompatibilityBinPatches() {
-        group = 'jar compatibility'
-        onlyIf {
-            inputVersion.getOrNull() != null
-        }
-
-        output.convention(project.layout.buildDirectory.dir(name).map { it.file('joined.lzma') })
-    }
-
-    @TaskAction
-    void run() {
-        def dep = project.dependencies.create("net.minecraftforge:forge:${inputVersion.get()}:userdev")
-        def baseForgeUserdev = project.configurations.detachedConfiguration(dep).resolve().iterator().next()
-
-        def joinedLzma = project.zipTree(baseForgeUserdev).matching { it.include('joined.lzma') }.singleFile
-
-        Files.copy(joinedLzma.toPath(), output.get().asFile.toPath())
-    }
-
-    @Input
-    @Optional
-    abstract Property<String> getInputVersion()
-
-    @OutputFile
-    abstract RegularFileProperty getOutput()
-}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/InheritanceData.groovy

@@ -0,0 +1,49 @@
+package net.minecraftforge.forge.tasks
+
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import groovy.transform.CompileStatic
+import groovy.transform.TupleConstructor
+
+@CompileStatic
+@TupleConstructor
+final class InheritanceData implements Annotatable {
+    String name
+    int access
+    String superName
+    List<String> interfaces = []
+    Map<String, Method> methods = [:]
+    Map<String, Field> fields = [:]
+    List<Annotation> annotations = []
+
+    @TupleConstructor
+    static final class Method implements Annotatable {
+        int access
+        String override
+        List<Annotation> annotations = []
+    }
+
+    @TupleConstructor
+    static final class Field implements Annotatable {
+        int access
+        String desc
+        List<Annotation> annotations = []
+    }
+
+    @TupleConstructor
+    static final class Annotation {
+        String desc
+    }
+
+    private static final Gson GSON = new Gson()
+    static Map<String, InheritanceData> parse(File file) {
+        try (final reader = file.newReader()) {
+            return GSON.fromJson(reader, new TypeToken<Map<String, InheritanceData>>() {})
+        }
+    }
+}
+
+@CompileStatic
+interface Annotatable {
+    List<InheritanceData.Annotation> getAnnotations()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/MergeJars.groovy

@@ -0,0 +1,44 @@
+package net.minecraftforge.forge.tasks
+
+import org.apache.commons.io.IOUtils
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+import java.util.zip.ZipOutputStream
+
+abstract class MergeJars extends DefaultTask {
+    MergeJars() {
+        output.convention(project.layout.buildDirectory.dir(name).map { it.file('output.jar') })
+    }
+
+    @TaskAction
+    void run() {
+        def jars = inputJars.files
+
+        try (ZipOutputStream zout = new ZipOutputStream(new FileOutputStream(output.get().asFile))) {
+            for (def jar : jars) {
+                try (ZipInputStream zin = new ZipInputStream(new FileInputStream(jar))) {
+                    def entry
+                    while ((entry = zin.getNextEntry()) != null) {
+                        ZipEntry _new = new ZipEntry(entry.getName())
+                        _new.setTime(0) //SHOULD be the same time as the main entry, but NOOOO _new.setTime(entry.getTime()) throws DateTimeException, so you get 0, screw you!
+                        zout.putNextEntry(_new)
+                        IOUtils.copy(zin, zout)
+                    }
+                }
+            }
+        }
+    }
+
+    @InputFiles
+    abstract ConfigurableFileCollection getInputJars()
+
+    @OutputFile
+    abstract RegularFileProperty getOutput()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/SetupCheckJarCompatibility.groovy

@@ -0,0 +1,57 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.artifacts.Dependency
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+
+abstract class SetupCheckJarCompatibility extends DefaultTask {
+    SetupCheckJarCompatibility() {
+        group = 'jar compatibility'
+        onlyIf {
+            inputVersion.getOrNull() != null
+        }
+        outputs.upToDateWhen { false } // Never up to date, because this setup task should always run
+
+        baseBinPatchesOutput.convention(project.layout.buildDirectory.dir(name).map { it.file('joined.lzma') })
+    }
+
+    @TaskAction
+    void run() {
+        def inputVersion = inputVersion.get()
+        def fmlLibs = project.configurations.detachedConfiguration(project.PACKED_DEPS.collect {
+            def artifactId = it.split(':')[1]
+            return project.dependencies.create("net.minecraftforge:${artifactId}:${inputVersion}")
+        }.toArray(Dependency[]::new))
+
+        project.tasks.named('checkJarCompatibility') {
+            baseLibraries.from(project.provider {
+                fmlLibs.resolvedConfiguration.lenientConfiguration.files
+            })
+        }
+
+        def baseForgeUserdev = project.layout.buildDirectory.dir(name).map { it.file("forge-${inputVersion}-userdev.jar") }.get().asFile
+        project.rootProject.extensions.download.run {
+            src "https://maven.minecraftforge.net/net/minecraftforge/forge/${inputVersion}/forge-${inputVersion}-userdev.jar"
+            dest baseForgeUserdev
+        }
+
+        def joinedLzma = project.zipTree(baseForgeUserdev).matching { it.include('joined.lzma') }.singleFile
+
+        Files.copy(joinedLzma.toPath(), baseBinPatchesOutput.get().asFile.toPath(), StandardCopyOption.REPLACE_EXISTING)
+    }
+
+    @Input
+    @Optional
+    abstract Property<String> getInputVersion()
+
+    @OutputFile
+    abstract RegularFileProperty getBaseBinPatchesOutput()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/TeamcityRequests.groovy

@@ -0,0 +1,74 @@
+package net.minecraftforge.forge.tasks
+
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import groovy.transform.CompileStatic
+import org.eclipse.jgit.api.Git
+
+import javax.annotation.Nullable
+import java.util.stream.Collectors
+
+@CompileStatic
+class TeamcityRequests {
+    public static final Gson GSON = new Gson()
+
+    @Nullable
+    static <T> T jsonRequest(TypeToken<T> clazz, String url) throws Exception {
+        final HttpURLConnection conn = (HttpURLConnection) URI.create(url).toURL().openConnection()
+        conn.setRequestProperty('Accept', 'application/json')
+        conn.setReadTimeout(5 * 1000)
+        conn.setConnectTimeout(5 * 1000)
+        conn.connect()
+
+        if (conn.responseCode !== 200) {
+            return null
+        }
+
+        try (final InputStream is = conn.getInputStream()) {
+            GSON.fromJson(new InputStreamReader(is), clazz.getType())
+        }
+    }
+
+    @Nullable
+    static Map<String, Build> buildsByCommit() throws IOException {
+        final Map<String, Build> builds = [:]
+        jsonRequest(new TypeToken<Builds>() {}, "https://teamcity.minecraftforge.net/guestAuth/app/rest/builds?fields=build:(revisions,number)&locator=buildType:(id:MinecraftForge_MinecraftForge_MinecraftForge_MinecraftForge__Build),count:300,status:SUCCESS")
+                ?.build?.forEach {
+            it.revisions.revision.each { rev -> builds[rev.version] = it }
+        }
+        return builds
+    }
+
+    @Nullable
+    static String attemptFindBase(File gitPath) {
+        try (final git = Git.open(gitPath)) {
+            final Map<String, Build> buildByCommit = buildsByCommit()
+            for (final commit in git.log().setMaxCount(100).call()) {
+                // Find the first commit which was built on CI
+                final build = buildByCommit[commit.id.name]
+                if (build) {
+                    return build.number
+                }
+            }
+        } catch (Exception ignored) {}
+        return null
+    }
+
+    static final class Builds {
+        public List<Build> build
+    }
+
+    static final class Build {
+        public String number
+        public Revisions revisions
+    }
+
+    static final class Revisions {
+        public int count
+        public List<Revision> revision
+    }
+
+    static final class Revision {
+        public String version
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/Util.groovy

@@ -18,17 +18,17 @@ public class Util {
 			return md.digest().collect {String.format "%02x", it}.join()
 		}
         File.metaClass.getSha1 = { !delegate.exists() ? null : delegate.sha1() }
-	
+
 		File.metaClass.json = { -> new JsonSlurper().parseText(delegate.text) }
         File.metaClass.getJson = { return delegate.exists() ? new JsonSlurper().parse(delegate) : [:] }
         File.metaClass.setJson = { json -> delegate.text = new JsonBuilder(json).toPrettyString() }
-		
+
 		Date.metaClass.iso8601 = { ->
 			def format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ")
 			def result = format.format(delegate)
 			return result[0..21] + ':' + result[22..-1]
 		}
-        
+
         String.metaClass.rsplit = { String del, int limit = -1 ->
             def lst = new ArrayList()
             def x = 0, idx
@@ -41,7 +41,7 @@ public class Util {
             return lst
         }
 	}
-	
+
 	public static String[] getClasspath(project, libs, artifact) {
 		def ret = []
 		artifactTree(project, artifact).each { key, lib ->
@@ -51,7 +51,7 @@ public class Util {
 		}
 		return ret
 	}
-	
+
 	public static def getArtifacts(project, config, classifiers) {
 		def ret = [:]
 		config.resolvedConfiguration.resolvedArtifacts.each {
@@ -75,7 +75,7 @@ public class Util {
 				url = "https://maven.minecraftforge.net/${path}"
 			}
 			//TODO remove when Mojang launcher is updated
-			if (!classifiers && art.classifier != null) { 
+			if (!classifiers && art.classifier != null) {
 				//Mojang launcher doesn't currently support classifiers, so... move it to part of the version, and force the extension to 'jar'
 				// However, keep the path normal so that our mirror system works.
 				art.version = "${art.version}-${art.classifier}"
@@ -96,14 +96,14 @@ public class Util {
 		}
 		return ret
 	}
-    
-    public static def getMavenPath(task) {        
+
+    public static def getMavenPath(task) {
         def classifier = task.archiveClassifier.get()
         def dep = "${task.project.group}:${task.project.name}:${task.project.version}" + (classifier == '' ? '' : ':' + classifier)
         return "${task.project.group.replace('.', '/')}/${task.project.name}/${task.project.version}/${task.project.name}-${task.project.version}".toString() + (classifier == '' ? '' : '-' + classifier) + '.jar'
     }
-    
-    public static def getMavenDep(task) {        
+
+    public static def getMavenDep(task) {
         def classifier = task.archiveClassifier.get()
         return "${task.project.group}:${task.project.name}:${task.project.version}" + (classifier == '' ? '' : ':' + classifier)
     }
@@ -127,7 +127,7 @@ public class Util {
 		def files = cfg.resolve()
 		return getArtifacts(project, cfg, true)
 	}
-	
+
 	private static boolean checkExists(url) {
 		try {
 			def code = new URL(url).openConnection().with {
@@ -142,4 +142,10 @@ public class Util {
 			throw e
 		}
 	}
+
+    static String getLatestForgeVersion(mcVersion) {
+        final json = new JsonSlurper().parseText(new URL('https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json').getText('UTF-8'))
+        final ver = json.promos["$mcVersion-latest"]
+        ver === null ? null : (mcVersion + '-' + ver)
+    }
 }

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckATs.groovy

@@ -0,0 +1,310 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import groovy.transform.TupleConstructor
+import net.minecraftforge.forge.tasks.InheritanceData
+import net.minecraftforge.srgutils.IMappingFile
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFile
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
+import org.objectweb.asm.Opcodes
+
+@CompileStatic
+abstract class CheckATs extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getInheritance()
+    @InputFiles abstract ConfigurableFileCollection getAts()
+    @InputFile @Optional abstract RegularFileProperty getMappings()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final IMappingFile mappings = mappings.map { RegularFile it -> IMappingFile.load(it.asFile) }.getOrNull()
+        final inheritance = InheritanceData.parse(this.inheritance.get().asFile)
+
+        ats.each {
+            final lines = process(it, reporter, inheritance)
+            if (fix) {
+                it.text = joinBack(lines, inheritance, mappings).join('\n')
+            }
+        }
+    }
+
+    private static TreeMap<String, ATParser.Entry> process(File file, Reporter reporter, Map<String, InheritanceData> inheritance) {
+        final TreeMap<String, ATParser.Entry> lines = ATParser.parse(file.readLines(), reporter)
+        final Map<String, ATParser.Entry> constructorGroups = [:]
+
+        final itr = lines.entrySet().iterator()
+        final toRemove = []
+        while (itr.hasNext()) {
+            final next = itr.next()
+            String key = next.key
+            final entry = next.value
+            if (entry === null) continue
+
+            final binaryName = entry.cls.replaceAll('\\.', '/')
+
+            // Process Groups, this will remove any entries outside the group that is covered by the group
+            if (entry.group) {
+                final jcls = inheritance[binaryName]
+                if (jcls === null) {
+                    itr.remove()
+                    reporter.report("Invalid group: $key")
+                } else if ('*' == entry.desc) {
+                    if (!jcls.fields) {
+                        itr.remove()
+                        reporter.report("Invalid group, class has no fields: $key")
+                    } else {
+                        jcls.fields.each { field, value ->
+                            final fkey = entry.cls + ' ' + field
+                            if (accessLevel(value.access) < accessStr(entry.modifier)) {
+                                if (lines.containsKey(fkey)) {
+                                    toRemove.add(fkey)
+                                } else if (!entry.existing.contains(fkey)) {
+                                    reporter.report("Missing group entry: $fkey")
+                                }
+                                entry.children.add(fkey)
+                            } else if (lines.containsKey(fkey)) {
+                                toRemove.add(fkey)
+                                reporter.report("Found invalid group entry: $fkey")
+                            }
+                        }
+                        entry.existing.findAll { it !in entry.children }.each { println('Removed: ' + it) }
+                    }
+                } else if ('*()' == entry.desc) {
+                    if (!jcls.methods) {
+                        itr.remove()
+                        reporter.report("Invalid group, class has no methods: $key")
+                    } else {
+                        jcls.methods.each { mtd, value ->
+                            if (mtd.startsWith('<clinit>') || mtd.startsWith('lambda$')) return
+                            key = entry.cls + ' ' + mtd.replace(' ', '')
+                            if (accessLevel(value.access) < accessStr(entry.modifier)) {
+                                if (lines.containsKey(key)) {
+                                    toRemove.add(key)
+                                } else if (!entry.existing.contains(key)) {
+                                    reporter.report("Missing group entry: $key")
+                                }
+                                entry.children.add(key)
+                            } else if (lines.containsKey(key)) {
+                                toRemove.add(key)
+                                reporter.report("Found invalid group entry: $key")
+                            }
+                        }
+                        entry.existing.findAll { it !in entry.children }.each { println('Removed: ' + it) }
+                    }
+                } else if ('<init>' == entry.desc) { //Make all public non-abstract subclasses
+                    constructorGroups.put(binaryName, entry)
+                }
+            }
+
+            // Process normal lines, remove invalid and remove narrowing
+            else {
+                def jcls = inheritance.get(binaryName)
+                if (jcls === null) {
+                    itr.remove()
+                    reporter.report("Invalid: $key")
+                } else if (entry.desc == '') {
+                    if (accessLevel(jcls.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                        itr.remove()
+                        reporter.report("Invalid Narrowing: $key")
+                    }
+                } else if (!entry.desc.contains('(')) {
+                    if (!jcls.fields || !jcls.fields.containsKey(entry.desc)) {
+                        itr.remove()
+                        reporter.report("Invalid: $key")
+                    } else {
+                        final value = jcls.fields[entry.desc]
+                        if (accessLevel(value.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                            itr.remove()
+                            reporter.report("Invalid Narrowing: $key - ${entry.comment}")
+                        }
+                    }
+                } else {
+                    final jdesc = entry.desc.replace('(', ' (')
+                    if (!jcls.methods || !jcls.methods.containsKey(jdesc)) {
+                        itr.remove()
+                        reporter.report("Invalid: $key")
+                    } else {
+                        final value = jcls.methods[jdesc]
+                        if (accessLevel(value.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                            itr.remove()
+                            reporter.report("Invalid Narrowing: $key")
+                        }
+                    }
+                }
+            }
+        }
+
+        inheritance.each { tcls, value ->
+            if (!value.methods || ((value.access & Opcodes.ACC_ABSTRACT) !== 0)) return
+            String parent = tcls
+            while (parent !== null) {
+                constructorGroups[parent]?.tap { entry ->
+                    value.methods.each { mtd, v ->
+                        if (mtd.startsWith('<init>')) {
+                            final child = tcls.replaceAll('/', '\\.') + ' ' + mtd.replace(' ', '')
+                            if (accessLevel(v.access) < 3) {
+                                if (lines.containsKey(child)) {
+                                    toRemove.add(child)
+                                } else if (child !in entry.existing) {
+                                    reporter.report("Missing group entry: $child")
+                                }
+                                entry.children.add(child)
+                            } else if (lines.containsKey(child)) {
+                                toRemove.add(child)
+                                reporter.report("Found invalid group entry: $child")
+                            }
+                        }
+                    }
+                }
+                parent = inheritance[parent]?.superName
+            }
+        }
+        constructorGroups.values().each { entry -> entry.existing.findAll { it !in entry.children }.each{  reporter.report("Found invalid group entry: $it") } }
+
+        toRemove.each(lines.&remove)
+
+        return lines
+    }
+
+    private static List<String> joinBack(TreeMap<String, ATParser.Entry> lines, Map<String, InheritanceData> inheritance, IMappingFile mappings) {
+        final List<String> data = []
+        final remapComment = { ATParser.Entry entry ->
+            if (!mappings || !entry || !entry.desc) return null
+            final comment = entry.comment?.substring(1)?.trim()
+            final jsonCls = inheritance.get(entry.cls.replaceAll('\\.', '/'))
+            final mappingsClass = mappings?.getClass(jsonCls.name)
+            if (mappingsClass === null) return entry.comment
+            final idx = entry.desc.indexOf('(')
+
+            String mappedName = idx == -1
+                    ? mappingsClass.remapField(entry.desc)
+                    : mappingsClass.remapMethod(entry.desc.substring(0, idx), entry.desc.substring(idx))
+            if (!mappedName) return entry.comment
+            if (mappedName == '<init>')
+                mappedName = 'constructor'
+
+            if (comment?.startsWith(mappedName))
+                return '# ' + comment
+            if (comment && comment.indexOf(' ') !== -1) {
+                def split = comment.split(' - ').toList()
+                if (split[0].indexOf(' ') !== -1)
+                // The first string is more than one word, so append before it
+                    return "# ${mappedName} - ${comment}"
+                split.remove(0)
+                return "# ${mappedName} - ${String.join(' - ', split)}"
+            }
+            return '# ' + mappedName
+        }
+        lines.each { key, value ->
+            if (!value.group) {
+                def comment = remapComment.call(value)
+                data.add(value.modifier + ' ' + key + (comment ? ' ' + comment : ''))
+            } else {
+                data.add(('#group ' + value.modifier + ' ' + key + ' ' + (value.comment ?: '')).trim())
+                value.children.each {
+                    final line = value.modifier + ' ' + it
+                    final entry = ATParser.parseEntry(line)
+                    final comment = remapComment(entry)
+                    data.add(line + (comment ? ' ' + comment : ''))
+                }
+                data.add('#endgroup')
+            }
+        }
+        return data
+    }
+
+    static int accessStr(String access) {
+        if (access.endsWith('-f') || access.endsWith('+f')) return 4
+        switch (access.toLowerCase()) {
+            case 'public':    return 3
+            case 'protected': return 2
+            case 'default':   return 1
+            case 'private':   return 0
+            default:          return -1
+        }
+    }
+
+    static int accessLevel(int access) {
+        if ((access & Opcodes.ACC_PUBLIC)    !== 0) return 3
+        if ((access & Opcodes.ACC_PROTECTED) !== 0) return 2
+        if ((access & Opcodes.ACC_PRIVATE)   !== 0) return 0
+        return 1
+    }
+}
+
+@CompileStatic
+class ATParser {
+    static TreeMap<String, Entry> parse(List<String> lines, CheckTask.Reporter reporter) {
+        TreeMap<String, Entry> outLines = new TreeMap<>()
+        Entry group = null
+        for (final line : lines) {
+            if (line.isEmpty()) continue
+            if (line.startsWith('#group ')) {
+                final entry = parseEntry(line.substring(7))
+
+                if (entry.desc != '*' && entry.desc != '*()' && entry.desc != '<init>') {
+                    reporter.report("Invalid group: $line", false)
+                }
+
+                entry.group = true
+                entry.children = []
+                entry.existing = []
+
+                group = entry
+
+                if (outLines.containsKey(entry.key)) {
+                    reporter.report("Duplicate group: $line", false)
+                }
+
+                outLines[entry.key] = group
+            } else if (group !== null) {
+                if (line.startsWith('#endgroup')) {
+                    group = null
+                } else {
+                    final key = parseEntry(line).key
+                    group.existing.add(key)
+                }
+            } else if (line.startsWith('#endgroup')) {
+                reporter.report("Invalid group ending: $line", false)
+            } else if (line.startsWith('#')) {
+                //Nom
+            } else {
+                final entry = parseEntry(line)
+                if (outLines.containsKey(entry.key)) {
+                    reporter.report("Found duplicate: $line")
+                    continue
+                }
+                outLines[entry.key] = entry
+            }
+        }
+        return outLines
+    }
+
+    static Entry parseEntry(String line) {
+        final idx = line.indexOf('#')
+        final String comment = idx === -1 ? null : line.substring(idx)
+        if (idx !== -1) line = line.substring(0, idx - 1)
+        final data = (line.trim() + '     ').split(' ', -1)
+        new Entry(data[0], data[1], data[2], comment)
+    }
+
+    @TupleConstructor
+    static final class Entry {
+        String modifier, cls, desc, comment
+
+        Set<String> existing
+        TreeSet<String> children
+        boolean group = false
+
+        @Lazy
+        String key = {cls + (desc.isEmpty() ? '' : ' ' + desc)}()
+
+        Object getAt(String key) {
+            return getProperty(key)
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckExcs.groovy

@@ -0,0 +1,93 @@
+package net.minecraftforge.forge.tasks.checks
+
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.ClassVisitor
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.Type
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+
+abstract class CheckExcs extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getBinary()
+    @InputFiles abstract ConfigurableFileCollection getExcs()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final Set<String> known = []
+        collectKnown(known)
+
+        excs.each { f ->
+            final lines = []
+            f.eachLine { line ->
+                def idx = line.indexOf('#')
+                if (idx == 0 || line.isEmpty()) {
+                    return
+                }
+
+                if (idx != -1) line = line.substring(0, idx - 1)
+
+                if (!line.contains('=')) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+
+                def (String key, String value) = line.split('=', 2)
+                if (!known.contains(key)) {
+                    reporter.report("Unknown: $line")
+                    return
+                }
+
+                String desc = key.split('\\.', 2)[1]
+                if (!desc.contains('(')) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+                desc = '(' + desc.split('\\(', 2)[1]
+
+                def (exceptions, String args) = value.contains('|') ? value.split('|', 2) : [value, '']
+
+                if (args.split(',').length !== Type.getArgumentTypes(desc).length) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+                lines.add(line)
+            }
+
+            if (fix) f.text = lines.sort().join('\n')
+        }
+    }
+
+    private void collectKnown(Collection<String> known) {
+        binary.get().asFile.withInputStream { i ->
+            new ZipInputStream(i).withCloseable { zin ->
+                final visitor = new ClassVisitor(Opcodes.ASM9) {
+                    private String cls
+                    @Override
+                    void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+                        this.cls = name
+                    }
+
+                    @Override
+                    MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+                        known.add(this.cls + '.' + name + descriptor)
+                        super.visitMethod(access, name, descriptor, signature, exceptions)
+                    }
+                }
+                ZipEntry zein
+                while ((zein = zin.nextEntry) !== null) {
+                    if (zein.name.endsWith('.class')) {
+                        ClassReader reader = new ClassReader(zin)
+                        reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES)
+                    }
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckMode.groovy

@@ -0,0 +1,9 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+
+@CompileStatic
+enum CheckMode {
+    CHECK,
+    FIX
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckPatches.groovy

@@ -0,0 +1,177 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.provider.ListProperty
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputDirectory
+import org.gradle.api.tasks.Optional
+
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.regex.Pattern
+
+@CompileStatic
+abstract class CheckPatches extends CheckTask {
+
+    private static final Pattern HUNK_START_PATTERN = Pattern.compile('^@@ -[0-9,]* \\+[0-9,_]* @@$')
+    private static final Pattern WHITESPACE_PATTERN = Pattern.compile('^[+\\-]\\s*$')
+    private static final Pattern IMPORT_PATTERN = Pattern.compile('^[+\\-]\\s*import.*')
+    private static final Pattern FIELD_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^=;]*)(=.*)?;\\s*$')
+    private static final Pattern METHOD_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^(]*)[(]([^)]*)?[)]\\s*[{]\\s*$')
+    private static final Pattern CLASS_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final[\\s]*)?(class|interface)([^{]*)[{]\\s*$')
+    private static final Map<String, Integer> ACCESS_MAP = [private: 0, protected: 2, public: 3].tap { it.put(null, 1) }
+
+    @InputDirectory abstract DirectoryProperty getPatchDir()
+    @Input @Optional abstract ListProperty<String> getPatchesWithS2SArtifact()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final patchDir = getPatchDir().get().asFile.toPath()
+        Files.walk(patchDir).withCloseable {
+            it.filter(Files.&isRegularFile).forEach { path ->
+                final String relativeName = patchDir.relativize(path).toString()
+                verifyPatch(path, reporter, fix, relativeName, patchesWithS2SArtifact.get().contains(relativeName.replace('\\', '/')))
+            }
+        }
+    }
+
+    void verifyPatch(Path patch, Reporter reporter, boolean fix, String patchPath, boolean hasS2SArtifact) {
+        final oldFixedErrors = reporter.fixed.size()
+
+        final lines = Files.readAllLines(patch)
+
+        int hunksStart = 0
+        boolean onlyWhiteSpace = false
+
+        final List<String> newLines = []
+
+        // First two lines are file name ++/-- and we do not care
+        newLines.add(lines[0] + '\n')
+        newLines.add(lines[1] + '\n')
+
+        int i
+        for (i = 2; i < lines.size(); ++i) {
+            def line = lines[i]
+            newLines.add(line + '\n')
+
+            if (HUNK_START_PATTERN.matcher(line).find()) {
+                if (onlyWhiteSpace) {
+                    if (!hasS2SArtifact)
+                        reporter.report("Patch contains only white space hunk starting at line ${hunksStart + 1}, file: $patchPath")
+                    int toRemove = i - hunksStart
+                    while (toRemove-- > 0)
+                        newLines.remove(newLines.size() - 1)
+                }
+                hunksStart = i
+                onlyWhiteSpace = true
+                continue
+            }
+
+            if (line.startsWithAny('+','-')) {
+                def prefixChange = false
+                def prevLine = lines[i - 1]
+
+                if (line.charAt(0) == (char)'+' && prevLine.charAt(0) == (char)'-') {
+                    def prevTrim = prevLine.substring(1).replaceAll("\\s", "")
+                    def currTrim = line.substring(1).replaceAll("\\s", "")
+
+                    if (prevTrim == currTrim) {
+                        prefixChange = true
+                    }
+
+                    def pMatcher = FIELD_PATTERN.matcher(prevLine)
+                    def cMatcher = FIELD_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // = ...
+                            pMatcher.group(5) == cMatcher.group(5) && // field name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+
+                    pMatcher = METHOD_PATTERN.matcher(prevLine)
+                    cMatcher = METHOD_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // params
+                            pMatcher.group(5) == cMatcher.group(5) && // <T> void name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+
+                    pMatcher = CLASS_PATTERN.matcher(prevLine)
+                    cMatcher = CLASS_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // ClassName<> extends ...
+                            pMatcher.group(5) == cMatcher.group(5) && // class | interface
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+                }
+
+                if (line.charAt(0) == (char)'-' && i + 1 < lines.size()) {
+                    final nextLine = lines[i + 1]
+                    if (nextLine.charAt(0) == (char)'+') {
+                        final nextTrim = nextLine.substring(1).replaceAll("\\s", "")
+                        final currTrim = line.substring(1).replaceAll("\\s", "")
+
+                        if (nextTrim == currTrim) {
+                            prefixChange = true
+                        }
+                    }
+                }
+
+                final isWhiteSpaceChange = WHITESPACE_PATTERN.matcher(line).find()
+
+                if (!prefixChange && !isWhiteSpaceChange) {
+                    onlyWhiteSpace = hasS2SArtifact && IMPORT_PATTERN.matcher(line).find()
+                } else if (isWhiteSpaceChange) {
+                    final prevLineChange = prevLine.startsWithAny('+','-')
+                    final nextLineChange = i + 1 < lines.size() && lines[i + 1].startsWithAny('+','-')
+
+                    if (!prevLineChange && !nextLineChange) {
+                        reporter.report("Patch contains white space change in valid hunk at line ${i + 1}, file: $patchPath", false)
+                    }
+                }
+
+                if (line.contains('\t')) {
+                    reporter.report("Patch contains tabs on line ${i + 1}, file: $patchPath")
+                    line = line.replaceAll('\t', '    ')
+                    newLines.remove(newLines.size() - 1)
+                    newLines.add(line + '\n')
+                }
+
+                if (IMPORT_PATTERN.matcher(line).find() && !hasS2SArtifact) {
+                    reporter.report("Patch contains import change on line ${i + 1}, file: $patchPath", false)
+                }
+            }
+        }
+
+        if (onlyWhiteSpace) {
+            if (!hasS2SArtifact)
+                reporter.report("Patch contains only white space hunk starting at line ${hunksStart + 1}, file: $patchPath")
+            def toRemove = i - hunksStart;
+            while (toRemove-- > 0)
+                newLines.remove(newLines.size() - 1)
+        }
+
+        if ((reporter.fixed.size() > oldFixedErrors && fix) || hasS2SArtifact) {
+            if (newLines.size() <= 2) {
+                logger.lifecycle("Patch is now empty removing, file: {}", patchPath)
+                Files.delete(patch)
+            }
+            else {
+                if (!hasS2SArtifact)
+                    logger.lifecycle("*** Updating patch file. Please run setup then genPatches again. ***")
+                Files.newBufferedWriter(patch).withCloseable {
+                    newLines.each { l -> it.write(l) }
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckSAS.groovy

@@ -0,0 +1,110 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import net.minecraftforge.forge.tasks.Annotatable
+import net.minecraftforge.forge.tasks.InheritanceData
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+
+@CompileStatic
+abstract class CheckSAS extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getInheritance()
+    @InputFiles abstract ConfigurableFileCollection getSass()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final inheritance = InheritanceData.parse(this.inheritance.get().asFile)
+
+        sass.each { f ->
+            final lines = []
+            f.eachLine { line ->
+                if (line[0] == '\t') return // Skip any tabbed lines, those are ones we add
+                final idx = line.indexOf('#')
+                if (idx == 0 || line.isEmpty()) {
+                    lines.add(line)
+                    return
+                }
+                def comment = idx == -1 ? null : line.substring(idx)
+                if (idx != -1) line = line.substring(0, idx - 1)
+                final spl = (line.trim().replace('(', ' (') + '     ').split(' ', -1)
+                def (String cls, String name, String desc) = [spl[0], spl[1], spl[2]]
+                cls = cls.replaceAll('\\.', '/')
+
+                if (inheritance[cls] === null) {
+                    reporter.report("Invalid: $line")
+                } else if (name.isEmpty()) { //Class SAS
+                    final toAdd = []
+                    final clsSided = isSided(inheritance[cls])
+                    boolean sided = clsSided
+
+                    /* TODO: MergeTool doesn't do fields
+                    if (json[cls]['fields'] != null) {
+                        for (entry in json[cls]['fields']) {
+                            if (isSided(entry.value)) {
+                                sided = true
+                                toAdd.add('\t' + cls + ' ' + entry.key)
+                            }
+						}
+                    } */
+
+                    final clsInh = inheritance[cls]
+                    if (clsInh.methods) {
+                        for (entry in clsInh.methods) {
+                            if (isSided(entry.value)) {
+                                sided = true
+                                toAdd.add('\t' + cls + ' ' + entry.key.replaceAll(' ', ''))
+                                findChildMethods(inheritance, cls, entry.key).each { lines.add('\t' + it) }
+                                findChildMethods(inheritance, cls, entry.key).each { println(line + ' -- ' + it) }
+                            } else if (clsSided) {
+                                findChildMethods(inheritance, cls, entry.key).each { lines.add('\t' + it) }
+                                findChildMethods(inheritance, cls, entry.key).each { println(line + ' -- ' + it) }
+                            }
+                        }
+                    }
+
+                    if (sided) {
+                        lines.add(cls + (comment == null ? '' : ' ' + comment))
+                        lines.addAll(toAdd.sort())
+                    } else {
+                        reporter.report("Invalid: $line")
+                    }
+
+                } else if (desc.isEmpty()) { // Fields
+                    /* TODO: MergeTool doesn't do fields
+                    if (json[cls]['fields'] != null && isSided(json[cls]['fields'][name]))
+                        lines.add(cls + ' ' + name + (comment == null ? '' : ' ' + comment))
+                    else */
+                    reporter.report("Invalid: $line")
+                } else { // Methods
+                    final clsInh = inheritance[cls]
+                    if (clsInh.methods === null || !isSided(clsInh.methods[name + ' ' + desc]))
+                        reporter.report("Invalid: $line")
+                    else {
+                        lines.add(cls + ' ' + name + desc + (comment == null ? '' : ' ' + comment))
+                        findChildMethods(inheritance, cls, name + ' ' + desc).each { println(line + ' -- ' + it) }
+                        findChildMethods(inheritance, cls, name + ' ' + desc).each { lines.add('\t' + it) }
+                    }
+                }
+            }
+
+            if (fix) f.text = lines.join('\n')
+        }
+    }
+
+    protected static isSided(Annotatable annotatable) {
+        if (annotatable === null) return false
+        for (ann in annotatable.annotations) {
+            if ('Lnet/minecraftforge/api/distmarker/OnlyIn;' == ann.desc)
+                return true
+        }
+        return false
+    }
+    
+    protected static findChildMethods(Map<String, InheritanceData> json, String cls, String desc) {
+        return json.values().findAll{ it.methods != null && it.methods[desc] != null && it.methods[desc].override == cls && isSided(it.methods[desc]) }
+                .collect { it.name + ' ' + desc.replace(' ', '') } as TreeSet
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckTask.groovy

@@ -0,0 +1,109 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import net.minecraftforge.forge.tasks.Util
+import org.gradle.api.Action
+import org.gradle.api.DefaultTask
+import org.gradle.api.logging.LogLevel
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.TaskContainer
+import org.gradle.api.tasks.VerificationTask
+
+@CompileStatic
+abstract class CheckTask extends DefaultTask implements VerificationTask {
+    @Input
+    abstract Property<CheckMode> getMode()
+
+    private boolean ignoreFailures = false
+
+    @Input
+    @Override
+    boolean getIgnoreFailures() {
+        return ignoreFailures
+    }
+
+    @Override
+    void setIgnoreFailures(boolean ignoreFailures) {
+        this.ignoreFailures = ignoreFailures
+    }
+
+    @TaskAction
+    void run() {
+        Util.init()
+
+        final doFix = getMode().get() === CheckMode.FIX
+        final Reporter reporter = new Reporter(doFix)
+        check(reporter, doFix)
+        
+        if (reporter.messages) {
+            if (getMode().get() === CheckMode.CHECK) {
+                logger.error("Check task '{}' found errors:\n{}", name, reporter.messages.join('\n'))
+                if (!ignoreFailures) {
+                    throw new IllegalArgumentException("${reporter.messages.size()} errors were found!")
+                }
+            } else {
+                if (logger.isEnabled(LogLevel.DEBUG)) {
+                    logger.warn("Check task '{}' found {} errors and fixed {}:\n{}", name, reporter.messages.size(), reporter.fixed.size(), reporter.fixed.join('\n'))
+                } else {
+                    logger.warn("Check task '{}' found {} errors and fixed {}.", name, reporter.messages.size(), reporter.fixed.size())
+                }
+
+                if (reporter.notFixed) {
+                    logger.error('{} errors could not be fixed:\n{}', reporter.notFixed.size(), reporter.notFixed.join('\n'))
+                    if (!ignoreFailures) {
+                        throw new IllegalArgumentException("${reporter.notFixed.size()} errors which cannot be fixed were found!")
+                    }
+                }
+            }
+        }
+    }
+
+    abstract void check(Reporter reporter, boolean fix)
+
+    @CompileStatic
+    static final class Reporter {
+        final boolean trackFixed
+        Reporter(boolean trackFixed) {
+            this.trackFixed = trackFixed
+        }
+
+        public final List<String> messages = []
+
+        public final List<String> fixed = []
+        public final List<String> notFixed = []
+
+        void report(String message, boolean canBeFixed = true) {
+            messages.add(message)
+
+            if (trackFixed) {
+                if (canBeFixed) {
+                    fixed.add(message)
+                } else {
+                    notFixed.add(message)
+                }
+            }
+        }
+    }
+
+    static <T extends CheckTask> void registerTask(TaskContainer tasks, String taskName, @DelegatesTo.Target('type') Class<T> clazz,
+                                                   @DelegatesTo(genericTypeIndex = 0, target = 'type') Closure configuration) {
+        taskName = taskName.capitalize()
+        tasks.register("check$taskName", clazz) { CheckTask task ->
+            configuration.setDelegate((T) task)
+            configuration.call(task)
+            task.mode.set(CheckMode.CHECK)
+            task.group = 'checks'
+        }
+        tasks.named('checkAll').configure { it.dependsOn("check$taskName") }
+
+        tasks.register("checkAndFix$taskName", clazz) { CheckTask task ->
+            configuration.setDelegate((T) task)
+            configuration.call(task)
+            task.mode.set(CheckMode.FIX)
+            task.group = 'checks'
+        }
+        tasks.named('checkAllAndFix').configure { it.dependsOn("checkAndFix$taskName") }
+    }
+}

docs/CONTRIBUTING.md

@@ -1,11 +1,11 @@
 Contributing to Forge
 =====================
 
-1) Keep patches to Minecraft classes together. If you need a lot of things done, you may either add to relevant forge classes or make a new class. Try not to spread out your patches across multiple disjoint lines, as this makes maintenance of your patches difficult.
+1) Keep patches to Minecraft classes minimal. If you need a lot of things done, you may either add to relevant forge classes or make a new class.
 
-2) TODO: Test Mods
+2) An example mod must be provided for all PRs adding events/hooks to Forge. Whether it's a full mod using your proposed hooks, or just a pastebin containing a simple example, an example mod is required. Please also explain in detail what your new hook does.
 
-3) Follow the code style of the class you're working in (braces on newlines & spaces instead of tabs in Forge classes, inline brackets in patches, etc).
+3) Follow Forge coding guidelines (braces on newlines, spaces instead of tabs, etc)
 
 For more information, refer to [the wiki](https://github.com/MinecraftForge/MinecraftForge/wiki/If-you-want-to-contribute-to-Forge)
 

docs/README.md

@@ -4,14 +4,16 @@ MinecraftForge
 =============
 [![Stable Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json&label=Stable&prefix=1.18.2-&query=$.promos["1.18.2-recommended"]&color=brightgreen&logo=data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPHN2ZyBjbGFzcz0ic3ZnLWlubGluZS0tZmEgZmEtc3RhciBmYS13LTE4IiBhcmlhLWhpZGRlbj0idHJ1ZSIgZGF0YS1pY29uPSJzdGFyIiBkYXRhLXByZWZpeD0iZmFzIiBmb2N1c2FibGU9ImZhbHNlIiByb2xlPSJpbWciIHZpZXdCb3g9IjAgMCA1NzYgNTEyIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPgo8cGF0aCBkPSJNMjU5LjMgMTcuOEwxOTQgMTUwLjIgNDcuOSAxNzEuNWMtMjYuMiAzLjgtMzYuNyAzNi4xLTE3LjcgNTQuNmwxMDUuNyAxMDMtMjUgMTQ1LjVjLTQuNSAyNi4zIDIzLjIgNDYgNDYuNCAzMy43TDI4OCA0MzkuNmwxMzAuNyA2OC43YzIzLjIgMTIuMiA1MC45LTcuNCA0Ni40LTMzLjdsLTI1LTE0NS41IDEwNS43LTEwM2MxOS0xOC41IDguNS01MC44LTE3LjctNTQuNkwzODIgMTUwLjIgMzE2LjcgMTcuOGMtMTEuNy0yMy42LTQ1LjYtMjMuOS01Ny40IDB6IiBmaWxsPSJ3aGl0ZSIvPgo8L3N2Zz4K)](https://files.minecraftforge.net)
 [![Latest Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json&label=Latest&prefix=1.18.2-&query=$.promos["1.18.2-latest"]&color=blue&logo=data:image/svg+xml;base64,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
-)](https://files.minecraftforge.net) [![Discord](https://img.shields.io/discord/313125603924639766.svg?color=%237289da&label=Discord&logo=discord&logoColor=%237289da)](https://discord.gg/UvedJ9m) [![Support](https://img.shields.io/badge/Patreon-Support-orange.svg?logo=Patreon)](https://www.patreon.com/LexManos)
+)](https://files.minecraftforge.net) [![Discord](https://img.shields.io/discord/313125603924639766.svg?color=%237289da&label=Discord&logo=discord&logoColor=%237289da)][Discord] [![Support](https://img.shields.io/badge/Patreon-Support-orange.svg?logo=Patreon)](https://www.patreon.com/LexManos)
 
 Forge is a free, open-source modding API all of your favourite mods use!
 
-| Version |    Support    |
-|---------| ------------- |
-| 1.19.x  |    Active     |
-| 1.18.x  |    LTS        |
+|    Version    |    Support    |
+| ------------- | ------------- |
+|    1.20.x     |    Active     |
+|    1.19.x     |    Legacy     |
+|    1.18.x     |    Legacy     |
+|    1.16.x     |    Legacy     |
 
 * [Download]
 * [Forum]
@@ -28,39 +30,39 @@ You can download the installer for the *Recommended Build* or the
  more unstable as a result. The installer will attempt to install Forge
  into your vanilla launcher environment, where you can then create a new
  profile using that version and play the game!
- 
-For support and questions, visit [the Support Forum](https://www.minecraftforge.net/forum/forum/18-support-bug-reports/) or [the Forge Discord server](https://discord.gg/forge).
+
+For support and questions, visit [the Support Forum][Support-Forum] or [the Forge Discord server][Discord].
 
 [Here is a short video from Rorax showing how to install and setup Forge.](https://www.youtube.com/watch?v=lB3ArN_-3Oc)
 
 # Creating Mods
 
-[See the "Getting Started" section in the Forge Documentation](https://mcforge.readthedocs.io/en/latest/gettingstarted/).
+[See the "Getting Started" section in the Forge Documentation](https://docs.minecraftforge.net/en/1.18.x/gettingstarted/).
 
 # Contribute to Forge
 
 If you wish to actually inspect Forge, submit PRs or otherwise work
  with Forge itself, you're in the right place!
-
- [See the guide to setting up a Forge workspace](http://mcforge.readthedocs.io/en/latest/forgedev/).
+ 
+ [See the guide to setting up a Forge workspace](https://docs.minecraftforge.net/en/1.18.x/forgedev/).
 
 ### Pull requests
 
-[See the "Making Changes and Pull Requests" section in the Forge documentation](https://mcforge.readthedocs.io/en/latest/forgedev/#making-changes-and-pull-requests).
+[See the "Making Changes and Pull Requests" section in the Forge documentation](https://docs.minecraftforge.net/en/1.18.x/forgedev/#making-changes-and-pull-requests).
 
 Please read the contributing guidelines found [here](CONTRIBUTING.md) before making a pull request.
 
 ### Contributor License Agreement
-We require all contributors to acknowledge the [Forge Contributor License Agreement](https://cla-assistant.io/MinecraftForge/MinecraftForge). 
-Please ensure you have a valid email address associated with your GitHub account to do this. If you have previously 
+We require all contributors to acknowledge the [Forge Contributor
+ License Agreement](https://cla-assistant.io/MinecraftForge/MinecraftForge). Please ensure you have a valid email address
+ associated with your GitHub account to do this. If you have previously
  signed it, you should be OK.
 
 #### Donate
-*Forge is a large project with many collaborators working on it around the clock. Forge is and will always remain free 
- to use and modify. However, it costs money to run such a large project as this, so please consider 
- [becoming a patron](https://www.patreon.com/LexManos).*
+*Forge is a large project with many collaborators working on it around the clock. Forge is and will always remain free to use and modify. However, it costs money to run such a large project as this, so please consider [becoming a patron](https://www.patreon.com/LexManos).*
 
 [Download]: https://files.minecraftforge.net/
-[Forum]: https://www.minecraftforge.net/forum/
-[Discord]: https://discord.gg/UvedJ9m
-[Documentation]: https://mcforge.readthedocs.io
+[Forum]: https://forums.minecraftforge.net
+[Support-Forum]: https://forums.minecraftforge.net/forum/18-support-bug-reports/
+[Discord]: https://discord.minecraftforge.net
+[Documentation]: https://docs.minecraftforge.net/en/1.18.x/

docs/SUPPORT.md

@@ -76,7 +76,7 @@ If you're certain you've found an issue that is directly caused by Forge, you ha
 
  1. **Forge Forums:** There's a dedicated [Support & Bug Report](http://www.minecraftforge.net/forum/forum/18-support-bug-reports/) section on the Forge forums, which is led by team of moderators and volunteers who will try to deal with your reports as quickly as possible. *As a player you should probably report here first.*
    - For modders, there also is a separate [Modder Support](http://www.minecraftforge.net/forum/forum/70-modder-support/) section where you can ask all your development-related questions. *You should prefer this section for coding help.*
- 2. **Forge Discord Server:** You can find a lot of help on the official [Discord Server](https://discord.gg/forge), especially smaller issues that you quickly need help with. *Be aware that the channel is more suited towards development questions, so while you may get support there as a player, you should almost always prefer the forums.*
+ 2. **Forge IRC Channel:** You can find a lot of help on the official [`#minecraftforge`](irc://irc.esper.net:6667/minecraftforge) channel on EsperNet. Especially smaller issues that you quickly need help with could be reported there. *Be aware that the channel is more suited towards development questions, so while you may get support there as a player, you should almost always prefer the forums.*
  3. **Forge Issue Tracker:** If you're absolutely certain that you've found an issue in the Forge codebase (e.g. you're a modder yourself and have analyzed the stacktrace and relevant code), don't refrain from reporting it on this repository's [issue tracker](https://github.com/MinecraftForge/MinecraftForge/issues). *Please do not use the issues as a means of getting coding help. For developers, the IRC and the [official documentation](https://mcforge.readthedocs.io) are the best sources of information.*
 
 ### Mod Support
@@ -84,8 +84,7 @@ If you're certain you've found an issue that is directly caused by Forge, you ha
 A lot of mods also use GitHub or other source management systems and their integrated issue trackers. The following options will give you the best chances of reporting your issue in the right place:
 
  - **CurseForge:** Many mods are hosted on the [CurseForge platform](https://minecraft.curseforge.com) nowadays. Chances are you already downloaded them from there or as a part of a modpack hosted there. Projects may specify an issue reporting link on their own page, so simply look for it on the mod's project page and you should be directed to the preferred means of error reporting.
- - **Modrinth:** Some modders use [Modrinth](https://modrinth.com/mods) to host their mods, but be mindful that not all mods on this platform are for the Forge modloader.
- - **Searching for a repository directly:** You may need to try and find a repository directly on source control sites. The most common ones are [GitHub](https://github.com), [GitLab](https://gitlab.com), and [BitBucket](https://bitbucket.org). Both come with search capabilities, so simply try to search for the mod's name.
+ - **Searching for a repository directly:** You may need to try and find a repository directly on source control sites. The most common ones are [GitHub](https://github.com) and [BitBucket](https://bitbucket.org). Both come with search capabilities, so simply try to search for the mod's name.
 
 ### Vanilla Support
 

fmlcore/build.gradle

@@ -10,12 +10,10 @@ apply plugin: 'org.javamodularity.moduleplugin'
 dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
 
 dependencies {
-    compileOnly("org.jetbrains:annotations:${JETBRAINS_ANNOTATIONS_VERSION}")
-
-    api("net.minecraftforge:eventbus:${EVENTBUS_VERSION}")
-
+    compileOnly('org.jetbrains:annotations:21.0.1')
     implementation(project(':fmlloader'))
-    implementation("commons-io:commons-io:${COMMONS_IO_VERSION}")
+    api('net.minecraftforge:eventbus:5.0.+')
+    implementation('commons-io:commons-io:2.5')
 }
 
 task sourcesJar(type: Jar) {

fmlcore/src/main/java/net/minecraftforge/fml/IExtensionPoint.java

@@ -8,90 +8,62 @@ package net.minecraftforge.fml;
 import java.util.function.BiPredicate;
 import java.util.function.Supplier;
 
-/**
- * An extension point for a mod container.
- *
- * <p>An extension point can be registered for a mod container using {@link ModContainer#registerExtensionPoint(Class, Supplier)}
- * and retrieved (if present) using {@link ModContainer#getCustomExtension(Class)}. An extension point allows a mod to
- * supply an arbitrary value as a record class to another mod or framework through their mod container class, avoiding
- * the use of {@link InterModComms} or other external frameworks to pass around these values.</p>
- *
- * <p>The usual way to declare an extension point is to implement this interface on a record class, with the type
- * parameter being a reference to the class itself. For example, {@code record MyExtension(...) extends
- * IExtensionPoint<MyExtension>} would declare an extension point which supplies a {@code MyExtension} object. However,
- * there is no hard requirement that an extension point's type parameter must be in reference to itself; the type
- * parameter may reference another record class instead.</p>
- *
- * @param <T> the type of the record which is held by the extension point
- */
-@SuppressWarnings("unused") // Type parameter T
 public interface IExtensionPoint<T extends Record>
 {
     /**
-     * Extension point for the compatibility display test used on the server selection screen.
+     * Compatibility display test for the mod.
+     * Used for displaying compatibility with remote servers with the same mod, and on disk saves.
      *
-     * <em>Note: "server" and "client" refers to the {@linkplain net.minecraftforge.api.distmarker.Dist#DEDICATED_SERVER dedicated server}
-     * and {@linkplain net.minecraftforge.api.distmarker.Dist#CLIENT game client} physical distributions, rather than the
-     * {@linkplain LogicalSide logical server and client}.</em>
+     * The supplier provides my "local" version for sending across the impl or writing to disk
+     * The predicate tests the version from a remote instance or save for acceptability (Boolean is true for impl, false for local save)
+     * and returns true if the version is compatible.
      *
-     * <p>The {@link Supplier} provides the local compatibility version, which is sent from the server to the client
-     * for multiplayer connections or stored to disk for the world save. The {@link BiPredicate} accepts the remote
-     * compatibility version and a boolean indicating whether the remote version is from the server or a world save,
-     * where {@code true} means it is from the server and {@code false} means it is from the world save. The return
-     * value of the predicate determines whether the remote version is "compatible" for the purposes of the display test.</p>
+     * <p>Return {@code net.minecraftforge.network.NetworkConstants#IGNORESERVERONLY} in the supplier, if you wish to be ignored
+     * as a server side only mod.</p>
+     * <p>Return true in the predicate for all values of the input string (when impl boolean is true) if you are client side,
+     * and don't care about matching any potential server version.</p>
      *
-     * <p>The local compatibility version may be of the value {@link net.minecraftforge.network.NetworkConstants#IGNORESERVERONLY},
-     * in which case clients will ignore the mod's presence if it is present on the server but not on the client.
-     * However, the remote version test predicate must still accept this value as a remote version in order to display
-     * as compatible if the mod is present on the client.</p>
-     *
-     * <p><strong>The compatibility display test does not necessarily indicate the success or failure of an actual
-     * connection attempt.</strong> Factors such as display test extension misconfiguration, truncation of ping data,
-     * difference of registry data or network channels between server and client, and others may cause the result of the
-     * compatibility test to not reflect the actual likelihood of a connection successfully being established between
-     * the server and the client.</p>
-     *
-     * <p>An example declaration of a display test extension registration for a regular mod (requires to be present on
-     * server and client) is as follows:</p>
+     * <p>
+     * Examples: A server only mod
+     * </p>
      * <pre>{@code
-     * String compatibilityVersion = "1"; // Could be linked with a network channel version or mod version
-     * ModLoadingContext.get().registerExtensionPoint(IExtensionPoint.DisplayTest.class,
-     *         () -> new IExtensionPoint.DisplayTest(
-     *                 () -> compatibilityVersion,
-     *                 (remoteVersion, isFromServer) -> remoteVersion.equals(compatibilityVersion)
-     *         )
-     * );
+     *     registerExtensionPoint(DisplayTest.class, ()->new DisplayTest(
+     *      ()->NetworkConstants.IGNORESERVERONLY, // ignore me, I'm a server only mod
+     *      (s,b)->true // i accept anything from the server or the save, if I'm asked
+     *     )
      * }</pre>
      *
-     * <p>An example declaration of a display test extension registration for a <em>server-side-only</em> mod (does not
-     * require to be present on the client) is as follows:</p>
+     * <p>
+     * Examples: A client only mod
+     * </p>
      * <pre>{@code
-     * ModLoadingContext.get().registerExtensionPoint(IExtensionPoint.DisplayTest.class,
-     *         () -> new IExtensionPoint.DisplayTest(
-     *                 // Ignore this mod if not present on the client
-     *                 () -> NetworkConstants.IGNORESERVERONLY,
-     *                 // If present on the client, accept any version if from a server
-     *                 (remoteVersion, isFromServer) -> isFromServer
-     *         )
-     * );
+     *     registerExtensionPoint(DisplayTest.class, ()->new DisplayTest(
+     *      ()->"anything. i don't care", // if i'm actually on the server, this string is sent but i'm a client only mod, so it won't be
+     *      (remoteversionstring,networkbool)->networkbool // i accept anything from the server, by returning true if it's asking about the server
+     *     )
      * }</pre>
      *
-     * <p>An example declaration of a display test extension registration for a <em>client-side-only</em> mod (does not
-     * require to be present on the server) is as follows:</p>
-     * <pre>{@code
-     * ModLoadingContext.get().registerExtensionPoint(IExtensionPoint.DisplayTest.class,
-     *         () -> new IExtensionPoint.DisplayTest(
-     *                 // Send any version from server to client, since we will be accepting any version as well
-     *                 () -> "dQw4w9WgXcQ",
-     *                 // Accept any version on the client, from server or from save
-     *                 (remoteVersion, isFromServer) -> true
-     *         )
-     * );
-     * }</pre>
-     *
-     * @see net.minecraftforge.network.ServerStatusPing
-     * @see net.minecraftforge.client.ForgeHooksClient#processForgeListPingData(net.minecraft.network.protocol.status.ServerStatus, net.minecraft.client.multiplayer.ServerData)
      */
-    @SuppressWarnings("JavadocReference") // reference to NetworkConstants, ForgeHooksClient
-    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint<DisplayTest> {}
-}
+    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint<DisplayTest> {
+        public static final String IGNORESERVERONLY = "OHNOES\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31\uD83D\uDE31";
+
+        /**
+         * Ignores any version information coming from the server - use for server only mods
+         */
+        public static final Supplier<DisplayTest> IGNORE_SERVER_VERSION = () -> new DisplayTest(IGNORESERVERONLY, (remoteVersion, isFromServer) -> true);
+
+        /**
+         * Ignores all information and provides no information
+         */
+        public static final Supplier<DisplayTest> IGNORE_ALL_VERSION = () -> new DisplayTest("", (remoteVersion, isFromServer) -> true);
+
+        /**
+         * An optional alternative to {@link #DisplayTest(Supplier, BiPredicate)} which accepts a constant version string
+         * instead of a {@link Supplier}.
+         * <p>Internally, the provided version string is wrapped in a Supplier for you.</p>
+         */
+        public DisplayTest(String version, BiPredicate<String, Boolean> remoteVersionTest) {
+            this(() -> version, remoteVersionTest);
+        }
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/IModLoadingState.java

@@ -8,79 +8,23 @@ package net.minecraftforge.fml;
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.fml.event.IModBusEvent;
 
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
-/**
- * A mod loading state. During mod loading, the mod loader transitions between states in a defined sorted list of states,
- * grouped into various {@link ModLoadingPhase phases}.
- *
- * @see IModStateProvider
- */
 public interface IModLoadingState {
-    /**
-     * {@return the name of this state}
-     */
     String name();
-
-    /**
-     * {@return the name of the state immediately previous to this state} This may be a blank name, which indicates this
-     * is either the first mod loading state or an exceptional mod loading state (such as a situation where errors
-     * prevent the loading process from continuing normally).
-     */
     String previous();
-
-    /**
-     * {@return the mod loading phase this state belongs to} For exceptional mod loading states, this should be
-     * {@link ModLoadingPhase#ERROR}.
-     */
     ModLoadingPhase phase();
-
-    /**
-     * {@return a function returning a human-friendly message for this state}
-     */
     Function<ModList, String> message();
-
-    /**
-     * {@return an optional runnable, which runs before starting the transition from this state to the next}
-     * @see #buildTransition(Executor, Executor, Function, Function)
-     */
     Optional<Consumer<ModList>> inlineRunnable();
 
-    /**
-     * Builds the transition task for this state with a blank pre-sync and post-sync task.
-     *
-     * @param syncExecutor a synchronous executor
-     * @param parallelExecutor a parallel executor
-     * @param <T> a type of event fired on the mod-specific event bus
-     * @return a transition task for this state
-     * @see #buildTransition(Executor, Executor, Function, Function)
-     */
-    default <T extends Event & IModBusEvent>
-    Optional<CompletableFuture<Void>> buildTransition(final Executor syncExecutor,
-                                                      final Executor parallelExecutor) {
-        return buildTransition(syncExecutor, parallelExecutor,
-                e -> CompletableFuture.runAsync(() -> {}, e),
-                e -> CompletableFuture.runAsync(() -> {}, e));
+    default <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(final Executor syncExecutor, final Executor parallelExecutor) {
+        return buildTransition(syncExecutor, parallelExecutor, e->CompletableFuture.runAsync(()->{}, e), e->CompletableFuture.runAsync(()->{}, e));
     }
 
-    /**
-     * Builds the transition task for this state. The pre-sync and post-sync task functions allow the transition builder
-     * to run these tasks on the same executor as the actual event dispatch and pre/post hooks.
-     *
-     * @param syncExecutor a synchronous executor
-     * @param parallelExecutor a parallel executor
-     * @param preSyncTask a function which returns a task to run before event pre-dispatch hook
-     * @param postSyncTask a function which returns a task to run after event post-dispatch hook
-     * @param <T> a type of event fired on the mod-specific event bus
-     * @return a transition task for this state
-     */
-    <T extends Event & IModBusEvent>
-    Optional<CompletableFuture<Void>> buildTransition(final Executor syncExecutor,
-                                                      final Executor parallelExecutor,
-                                                      final Function<Executor, CompletableFuture<Void>> preSyncTask,
-                                                      final Function<Executor, CompletableFuture<Void>> postSyncTask);
+    <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(Executor syncExecutor, Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask);
 }

fmlcore/src/main/java/net/minecraftforge/fml/IModStateProvider.java

@@ -7,15 +7,6 @@ package net.minecraftforge.fml;
 
 import java.util.List;
 
-/**
- * Provides a list of mod loading states which the mod loader may transition between.
- *
- * <p>There may be multiple mod state providers in a single application, where all states from each provider is
- * combined into a single list and ordered.</p>
- */
 public interface IModStateProvider {
-    /**
-     * {@return the list of mod loading states known to this provider}
-     */
     List<IModLoadingState> getAllStates();
 }

fmlcore/src/main/java/net/minecraftforge/fml/IModStateTransition.java

@@ -9,6 +9,7 @@ import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.fml.event.IModBusEvent;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
@@ -23,26 +24,18 @@ public interface IModStateTransition {
         return new NoopTransition();
     }
 
-    default <T extends Event & IModBusEvent>
-    CompletableFuture<Void> build(final Executor syncExecutor,
-                                  final Executor parallelExecutor,
-                                  final Function<Executor, CompletableFuture<Void>> preSyncTask,
-                                  final Function<Executor, CompletableFuture<Void>> postSyncTask) {
-        List<CompletableFuture<Void>> futures = new ArrayList<>();
-
+    default <T extends Event & IModBusEvent> CompletableFuture<List<Throwable>> build(Executor syncExecutor, Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+        List<CompletableFuture<List<Throwable>>> cfs = new ArrayList<>();
         this.eventFunctionStream().get()
-                .map(f -> (EventGenerator<T>) f)
-                .reduce((head, tail) -> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, futures, head, ModLoadingStage::currentState, tail))
-                .ifPresent(last -> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, futures, last, nextModLoadingStage(), null));
-
+                .map(f->(EventGenerator<T>)f)
+                .reduce((head, tail)-> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, cfs, head, ModLoadingStage::currentState, tail))
+                .ifPresent(last-> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, cfs, last, nextModLoadingStage(), null));
         final CompletableFuture<Void> preSyncTaskCF = preSyncTask.apply(syncExecutor);
-        final CompletableFuture<Void> eventDispatchCF = ModList.gather(futures).thenCompose(ModList::completableFutureFromExceptionList);
-        final CompletableFuture<Void> postEventDispatchCF = preSyncTaskCF
-                .thenComposeAsync(n -> eventDispatchCF, parallelExecutor)
-                .thenApply(r -> {
-                    postSyncTask.apply(syncExecutor);
-                    return null;
-                });
+        final CompletableFuture<List<Throwable>> eventDispatchCF = ModList.gather(cfs).thenCompose(ModList::completableFutureFromExceptionList);
+        final CompletableFuture<List<Throwable>> postEventDispatchCF = preSyncTaskCF.thenComposeAsync(n -> eventDispatchCF, parallelExecutor).thenApply(r -> {
+            postSyncTask.apply(syncExecutor);
+            return r;
+        });
         return this.finalActivityGenerator().apply(syncExecutor, postEventDispatchCF);
     }
 
@@ -50,31 +43,18 @@ public interface IModStateTransition {
         return ModLoadingStage::nextState;
     }
 
-    private <T extends Event & IModBusEvent>
-    EventGenerator<T> addCompletableFutureTaskForModDispatch(final Executor syncExecutor,
-                                                             final Executor parallelExecutor,
-                                                             final List<CompletableFuture<Void>> completableFutures,
-                                                             final EventGenerator<T> eventGenerator,
-                                                             final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> nextState,
-                                                             final EventGenerator<T> nextGenerator) {
-        final Executor selectedExecutor = threadSelector().apply(syncExecutor, parallelExecutor);
-
-        var preDispatchHook = (BiFunction<Executor, EventGenerator<T>, CompletableFuture<Void>>) preDispatchHook();
-        completableFutures.add(preDispatchHook.apply(selectedExecutor, eventGenerator));
-
-        completableFutures.add(ModList.get().futureVisitor(eventGenerator, nextState).apply(threadSelector().apply(syncExecutor, parallelExecutor)));
-
-        var postDispatchHook = (BiFunction<Executor, EventGenerator<T>, CompletableFuture<Void>>) postDispatchHook();
-        completableFutures.add(postDispatchHook.apply(selectedExecutor, eventGenerator));
-
+    private <T extends Event & IModBusEvent> EventGenerator<T> addCompletableFutureTaskForModDispatch(final Executor syncExecutor, final Executor parallelExecutor, final List<CompletableFuture<List<Throwable>>> completeableFutures, final EventGenerator<T> eventGenerator, BiFunction<ModLoadingStage, Throwable, ModLoadingStage> nextState, final EventGenerator<T> nextGenerator) {
+        completeableFutures.add(((BiFunction<Executor, EventGenerator<T>, CompletableFuture<List<Throwable>>>)preDispatchHook()).apply(threadSelector().apply(syncExecutor, parallelExecutor), eventGenerator));
+        completeableFutures.add(ModList.get().futureVisitor(eventGenerator, nextState).apply(threadSelector().apply(syncExecutor, parallelExecutor)));
+        completeableFutures.add(((BiFunction<Executor, EventGenerator<T>, CompletableFuture<List<Throwable>>>)postDispatchHook()).apply(threadSelector().apply(syncExecutor, parallelExecutor), eventGenerator));
         return nextGenerator;
     }
 
     Supplier<Stream<EventGenerator<?>>> eventFunctionStream();
     ThreadSelector threadSelector();
-    BiFunction<Executor, CompletableFuture<Void>, CompletableFuture<Void>> finalActivityGenerator();
-    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<Void>> preDispatchHook();
-    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<Void>> postDispatchHook();
+    BiFunction<Executor, CompletableFuture<List<Throwable>>, CompletableFuture<List<Throwable>>> finalActivityGenerator();
+    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> preDispatchHook();
+    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> postDispatchHook();
 
     interface EventGenerator<T extends Event & IModBusEvent> extends Function<ModContainer, T> {
         static <FN extends Event & IModBusEvent> EventGenerator<FN> fromFunction(Function<ModContainer, FN> fn) {
@@ -96,17 +76,17 @@ record NoopTransition() implements IModStateTransition {
     }
 
     @Override
-    public BiFunction<Executor, CompletableFuture<Void>, CompletableFuture<Void>> finalActivityGenerator() {
+    public BiFunction<Executor, CompletableFuture<List<Throwable>>, CompletableFuture<List<Throwable>>> finalActivityGenerator() {
         return (e, t) -> t.thenApplyAsync(Function.identity(), e);
     }
 
     @Override
-    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<Void>> preDispatchHook() {
-        return (t, f)-> CompletableFuture.completedFuture(null);
+    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> preDispatchHook() {
+        return (t, f)-> CompletableFuture.completedFuture(Collections.emptyList());
     }
 
     @Override
-    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<Void>> postDispatchHook() {
-        return (t, f)-> CompletableFuture.completedFuture(null);
+    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> postDispatchHook() {
+        return (t, f)-> CompletableFuture.completedFuture(Collections.emptyList());
     }
 }

fmlcore/src/main/java/net/minecraftforge/fml/LogicalSide.java

@@ -5,41 +5,12 @@
 
 package net.minecraftforge.fml;
 
-import net.minecraftforge.api.distmarker.Dist;
-
-/**
- * A logical side of the Minecraft game.
- * <p>
- * The {@linkplain Dist#CLIENT client distribution} has a copy of the logical client and the logical server, while the
- * {@linkplain Dist#DEDICATED_SERVER dedicated server distribution} only holds
- * the logical server.
- *
- * @see Dist
- */
 public enum LogicalSide
 {
-    /**
-     * The logical client of the Minecraft game, which interfaces with the player's inputs and renders the player's
-     * viewpoint.
-     * <p>
-     * The logical client is only shipped with the client distribution of the game.
-     *
-     * @see Dist#CLIENT
-     */
-    CLIENT,
-    /**
-     * The logical server of the Minecraft game, responsible for connecting to clients and running the simulation logic
-     * on the level.
-     * <p>
-     * The logical server is shipped with both client and dedicated server distributions. The client distribution runs
-     * the logical server for singleplayer mode and LAN play.
-     *
-     * @see Dist#DEDICATED_SERVER
-     */
-    SERVER;
+    CLIENT, SERVER;
 
     /**
-     * {@return if this logical side is the server}
+     * @return if the logical side is a server.
      */
     public boolean isServer()
     {
@@ -47,7 +18,7 @@ public enum LogicalSide
     }
 
     /**
-     * {@return if the logical side is the client}
+     * @return if the logical side is a client.
      */
     public boolean isClient()
     {

fmlcore/src/main/java/net/minecraftforge/fml/ModContainer.java

@@ -20,6 +20,7 @@ import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.function.BiFunction;
+import java.util.function.BiPredicate;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -56,9 +57,24 @@ public abstract class ModContainer
         this.namespace = this.modId;
         this.modInfo = info;
         this.modLoadingStage = ModLoadingStage.CONSTRUCT;
-        // default displaytest extension checks for version string match
-        registerExtensionPoint(IExtensionPoint.DisplayTest.class, () -> new IExtensionPoint.DisplayTest(()->this.modInfo.getVersion().toString(),
-                (incoming, isNetwork)->Objects.equals(incoming, this.modInfo.getVersion().toString())));
+
+        final String displayTestString = info.getConfig().<String>getConfigElement("displayTest").orElse("MATCH_VERSION"); // missing defaults to DEFAULT type
+        Supplier<IExtensionPoint.DisplayTest> displayTestSupplier = switch (displayTestString) {
+            case "MATCH_VERSION" -> // default displaytest checks for version string match
+                    () -> new IExtensionPoint.DisplayTest(() -> this.modInfo.getVersion().toString(),
+                            (incoming, isNetwork) -> Objects.equals(incoming, this.modInfo.getVersion().toString()));
+            case "IGNORE_SERVER_VERSION" -> // Ignores any version information coming from the server - use for server only mods
+                    IExtensionPoint.DisplayTest.IGNORE_SERVER_VERSION;
+            case "IGNORE_ALL_VERSION" -> // Ignores all information and provides no information
+                    IExtensionPoint.DisplayTest.IGNORE_ALL_VERSION;
+            case "NONE" -> null; // NO display test at all - use this if you're going to do your own display test
+            default -> // any other value throws an exception
+                    throw new IllegalArgumentException("Invalid displayTest value supplied in mods.toml");
+        };
+        if (displayTestSupplier != null)
+            registerExtensionPoint(IExtensionPoint.DisplayTest.class, displayTestSupplier);
+        else
+            extensionPoints.remove(IExtensionPoint.DisplayTest.class);
     }
 
     /**
@@ -127,6 +143,22 @@ public abstract class ModContainer
         extensionPoints.put(point, extension);
     }
 
+    public void registerDisplayTest(IExtensionPoint.DisplayTest displayTest) {
+        registerExtensionPoint(IExtensionPoint.DisplayTest.class, () -> displayTest);
+    }
+
+    public void registerDisplayTest(Supplier<IExtensionPoint.DisplayTest> displayTest) {
+        registerExtensionPoint(IExtensionPoint.DisplayTest.class, displayTest);
+    }
+
+    public void registerDisplayTest(String version, BiPredicate<String, Boolean> remoteVersionTest) {
+        registerDisplayTest(new IExtensionPoint.DisplayTest(version, remoteVersionTest));
+    }
+
+    public void registerDisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) {
+        registerDisplayTest(new IExtensionPoint.DisplayTest(suppliedVersion, remoteVersionTest));
+    }
+
     public void addConfig(final ModConfig modConfig) {
        configs.put(modConfig.getType(), modConfig);
     }
@@ -153,4 +185,4 @@ public abstract class ModContainer
      * @param e Event to accept
      */
     protected <T extends Event & IModBusEvent> void acceptEvent(T e) {}
-}
+}

fmlcore/src/main/java/net/minecraftforge/fml/ModList.java

@@ -21,6 +21,7 @@ import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -110,7 +111,7 @@ public class ModList
         return this.fileById.get(modid);
     }
 
-    <T extends Event & IModBusEvent> Function<Executor, CompletableFuture<Void>> futureVisitor(
+    <T extends Event & IModBusEvent> Function<Executor, CompletableFuture<List<Throwable>>> futureVisitor(
             final IModStateTransition.EventGenerator<T> eventGenerator,
             final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> stateChange) {
         return executor -> gather(
@@ -119,12 +120,12 @@ public class ModList
                 .collect(Collectors.toList()))
             .thenComposeAsync(ModList::completableFutureFromExceptionList, executor);
     }
-    static CompletionStage<Void> completableFutureFromExceptionList(List<? extends Map.Entry<?, Throwable>> t) {
+    static CompletionStage<List<Throwable>> completableFutureFromExceptionList(List<? extends Map.Entry<?, Throwable>> t) {
         if (t.stream().noneMatch(e->e.getValue()!=null)) {
-            return CompletableFuture.completedFuture(null);
+            return CompletableFuture.completedFuture(Collections.emptyList());
         } else {
             final List<Throwable> throwables = t.stream().filter(e -> e.getValue() != null).map(Map.Entry::getValue).collect(Collectors.toList());
-            CompletableFuture<Void> cf = new CompletableFuture<>();
+            CompletableFuture<List<Throwable>> cf = new CompletableFuture<>();
             final RuntimeException accumulator = new RuntimeException();
             cf.completeExceptionally(accumulator);
             throwables.forEach(exception -> {

fmlcore/src/main/java/net/minecraftforge/fml/ModLoader.java

@@ -11,11 +11,11 @@ import net.minecraftforge.fml.event.IModBusEvent;
 import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.LoadingModList;
 import net.minecraftforge.fml.loading.moddiscovery.InvalidModIdentifier;
-import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
+import net.minecraftforge.forgespi.locating.IModFile;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -28,6 +28,7 @@ import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 import java.util.concurrent.Executor;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -196,7 +197,7 @@ public class ModLoader
         state.buildTransition(syncExecutor, parallelExecutor, preSyncTask, postSyncTask).ifPresent(t->waitForTransition(state, syncExecutor, ticker, t));
     }
 
-    private void waitForTransition(final IModLoadingState state, final ModWorkManager.DrivenExecutor syncExecutor, final Runnable ticker, final CompletableFuture<Void> transition) {
+    private void waitForTransition(final IModLoadingState state, final ModWorkManager.DrivenExecutor syncExecutor, final Runnable ticker, final CompletableFuture<List<Throwable>> transition) {
         while (!transition.isDone()) {
             syncExecutor.drive(ticker);
         }
@@ -222,7 +223,7 @@ public class ModLoader
         }
     }
 
-    private List<ModContainer> buildMods(final ModFile modFile)
+    private List<ModContainer> buildMods(final IModFile modFile)
     {
         final Map<String, IModInfo> modInfoMap = modFile.getModFileInfo().getMods().stream().collect(Collectors.toMap(IModInfo::getModId, Function.identity()));
 
@@ -244,7 +245,7 @@ public class ModLoader
         return containers.stream().filter(mc -> mc.modLoadingStage != ModLoadingStage.ERROR).collect(Collectors.toList());
     }
 
-    private ModContainer buildModContainerFromTOML(final ModFile modFile, final Map<String, IModInfo> modInfoMap, final Map.Entry<String, ? extends IModLanguageProvider.IModLanguageLoader> idToProviderEntry) {
+    private ModContainer buildModContainerFromTOML(final IModFile modFile, final Map<String, IModInfo> modInfoMap, final Map.Entry<String, ? extends IModLanguageProvider.IModLanguageLoader> idToProviderEntry) {
         try {
             final String modId = idToProviderEntry.getKey();
             final IModLanguageProvider.IModLanguageLoader languageLoader = idToProviderEntry.getValue();

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingContext.java

@@ -8,6 +8,7 @@ package net.minecraftforge.fml;
 import net.minecraftforge.fml.config.IConfigSpec;
 import net.minecraftforge.fml.config.ModConfig;
 
+import java.util.function.BiPredicate;
 import java.util.function.Supplier;
 
 public class ModLoadingContext
@@ -45,6 +46,44 @@ public class ModLoadingContext
         getActiveContainer().registerExtensionPoint(point, extension);
     }
 
+    /**
+     * Register a {@link IExtensionPoint.DisplayTest} with the mod container.
+     * <p>A shorthand for registering a DisplayTest with {@link #registerExtensionPoint(Class, Supplier)}.</p>
+     * @param displayTest The {@link IExtensionPoint.DisplayTest} to register
+     */
+    public void registerDisplayTest(IExtensionPoint.DisplayTest displayTest) {
+        getActiveContainer().registerDisplayTest(() -> displayTest);
+    }
+
+    /**
+     * Register a {@link IExtensionPoint.DisplayTest} with the mod container.
+     * <p>A shorthand for registering a DisplayTest supplier with {@link #registerExtensionPoint(Class, Supplier)}.</p>
+     * @param displayTest The {@link Supplier<IExtensionPoint.DisplayTest>} to register
+     */
+    public void registerDisplayTest(Supplier<IExtensionPoint.DisplayTest> displayTest) {
+        getActiveContainer().registerDisplayTest(displayTest);
+    }
+
+    /**
+     * Register a {@link IExtensionPoint.DisplayTest} with the mod container.
+     * <p>A shorthand for registering a DisplayTest with {@link #registerExtensionPoint(Class, Supplier)} that also
+     * creates the DisplayTest instance for you using the provided parameters.</p>
+     * @see IExtensionPoint.DisplayTest#DisplayTest(String, BiPredicate)
+     */
+    public void registerDisplayTest(String version, BiPredicate<String, Boolean> remoteVersionTest) {
+        getActiveContainer().registerDisplayTest(new IExtensionPoint.DisplayTest(version, remoteVersionTest));
+    }
+
+    /**
+     * Register a {@link IExtensionPoint.DisplayTest} with the mod container.
+     * <p>A shorthand for registering a DisplayTest with {@link #registerExtensionPoint(Class, Supplier)} that also
+     * creates the DisplayTest instance for you using the provided parameters.</p>
+     * @see IExtensionPoint.DisplayTest#DisplayTest(Supplier, BiPredicate)
+     */
+    public void registerDisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) {
+        getActiveContainer().registerDisplayTest(new IExtensionPoint.DisplayTest(suppliedVersion, remoteVersionTest));
+    }
+
     public void registerConfig(ModConfig.Type type, IConfigSpec<?> spec) {
         getActiveContainer().addConfig(new ModConfig(type, spec, getActiveContainer()));
     }

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingPhase.java

@@ -5,34 +5,10 @@
 
 package net.minecraftforge.fml;
 
-/**
- * Phases of mod loading, for grouping mod loading states.
- */
 public enum ModLoadingPhase {
-    /**
-     * Special phase for exceptional situations and error handling, where mod loading cannot continue normally.
-     *
-     * <p>There is conventionally only one state with this phase.</p>
-     */
     ERROR, // Special state for error handling
-    /**
-     * Phase for discovering and gathering mods for loading.
-     */
     GATHER,
-    /**
-     * Phase for the loading of mods found from mod discovery.
-     *
-     * @see #GATHER
-     */
     LOAD,
-    /**
-     * Phase after mod loading has completed, for post-loading tasks.
-     *
-     * @see #LOAD
-     */
     COMPLETE,
-    /**
-     * Marker phase for the last state in the full mod loading process.
-     */
-    DONE
+    DONE;
 }

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingStage.java

@@ -5,53 +5,16 @@
 
 package net.minecraftforge.fml;
 
-/**
- * Mod loading stage of mod containers during the mod loading process. These will have a corresponding {@link ModLoadingState}
- * in the basic mod loading process provided by FML.
- *
- * <p>Each mod loading stage has a global {@link DeferredWorkQueue}, which is populated during the execution of the state
- * associated with this stage and emptied at the end of the state's execution.</p>
- */
 public enum ModLoadingStage
 {
-    /**
-     * Special stage for exceptional situations and error handling.
-     */
     ERROR,
-    /**
-     * Validation of the mod list.
-     * TODO: figure out where this is used and why this exists instead of CONSTRUCT being the first normal stage
-     */
     VALIDATE,
-    /**
-     * Default stage of mod containers after construction.
-     */
     CONSTRUCT,
-    /**
-     * Common (non-side-specific) setup and initialization.
-     */
     COMMON_SETUP,
-    /**
-     * Side-specific setup and initialization.
-     *
-     * @see net.minecraftforge.api.distmarker.Dist
-     */
     SIDED_SETUP,
-    /**
-     * Stage for enqueuing {@link net.minecraftforge.fml.InterModComms} messages for later processing.
-     */
     ENQUEUE_IMC,
-    /**
-     * Stage for processing received messages though {@link net.minecraftforge.fml.InterModComms}.
-     */
     PROCESS_IMC,
-    /**
-     * Marks the completion of mod loading for this container.
-     */
     COMPLETE,
-    /**
-     * Marks the completion of the full mod loading process.
-     */
     DONE;
 
     private final DeferredWorkQueue deferredWorkQueue;
@@ -60,27 +23,14 @@ public enum ModLoadingStage
         deferredWorkQueue = new DeferredWorkQueue(this);
     }
 
-    /**
-     * {@return the next stage after this stage, or {@link #ERROR} if the exception is not {@code null}}
-     *
-     * @param exception the exception that occurred during this stage, may be {@code null}
-     */
     ModLoadingStage nextState(Throwable exception) {
         return exception != null ? ERROR : values()[this.ordinal()+1];
     }
 
-    /**
-     * {@return this stage, or {@link #ERROR} if the exception is not {@code null}}
-     *
-     * @param exception the exception that occurred during this stage, may be {@code null}
-     */
     public ModLoadingStage currentState(Throwable exception) {
         return exception != null ? ERROR : this;
     }
 
-    /**
-     * {@return the deferred work queue for this stage}
-     */
     public DeferredWorkQueue getDeferredWorkQueue() {
         return deferredWorkQueue;
     }

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingState.java

@@ -8,91 +8,31 @@ package net.minecraftforge.fml;
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.fml.event.IModBusEvent;
 
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
-/**
- * Implementation of the {@link IModLoadingState} interface.
- *
- * @param name           the name of this state
- * @param previous       the name of the state immediately previous to this state
- * @param message        a function returning a human-friendly message for this state
- * @param phase          the mod loading phase this state belongs to
- * @param inlineRunnable an optional runnable, which runs before starting the transition from this state to the next
- * @param transition     optional state transition information
- */
-public record ModLoadingState(String name, String previous,
-                              Function<ModList, String> message,
-                              ModLoadingPhase phase,
-                              Optional<Consumer<ModList>> inlineRunnable,
-                              Optional<IModStateTransition> transition) implements IModLoadingState {
+public record ModLoadingState(String name, String previous, Function<ModList, String> message, ModLoadingPhase phase, Optional<Consumer<ModList>> inlineRunnable, Optional<IModStateTransition> transition) implements IModLoadingState {
     @Override
-    public <T extends Event & IModBusEvent>
-    Optional<CompletableFuture<Void>> buildTransition(final Executor syncExecutor,
-                                                      final Executor parallelExecutor,
-                                                      final Function<Executor, CompletableFuture<Void>> preSyncTask,
-                                                      final Function<Executor, CompletableFuture<Void>> postSyncTask) {
-        return transition.map(t -> t.build(syncExecutor, parallelExecutor, preSyncTask, postSyncTask));
+    public <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(final Executor syncExecutor, final Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+        return transition.map(t->t.build(syncExecutor, parallelExecutor, preSyncTask, postSyncTask));
     }
 
-    /**
-     * {@return an empty mod loading state} The mod loading state has a blank human-readable message, no inline runnable,
-     * and no state transition information.
-     *
-     * @param name     the name of the state
-     * @param previous the name of the immediately previous state to this state
-     * @param phase    the mod loading phase the state belongs to
-     */
     public static ModLoadingState empty(final String name, final String previous, final ModLoadingPhase phase) {
-        return new ModLoadingState(name, previous, ml -> "", phase, Optional.empty(), Optional.empty());
+        return new ModLoadingState(name, previous, ml->"", phase, Optional.empty(), Optional.empty());
     }
 
-    /**
-     * Returns a mod loading state with state transition information and a default human-friendly message of
-     * {@code Processing transition [name]}.
-     *
-     * @param name       the name of the state
-     * @param previous   the name of the immediately previous state to this state
-     * @param phase      the mod loading phase the state belongs to
-     * @param transition the state transition information
-     * @return a mod loading state with state transition information and a default message
-     */
-    public static ModLoadingState withTransition(final String name, final String previous, final ModLoadingPhase phase,
-                                                 final IModStateTransition transition) {
-        return new ModLoadingState(name, previous, ml -> "Processing transition " + name, phase, Optional.empty(), Optional.of(transition));
+    public static ModLoadingState withTransition(final String name, final String previous, final ModLoadingPhase phase, IModStateTransition transition) {
+        return new ModLoadingState(name, previous, ml->"Processing transition "+name, phase, Optional.empty(), Optional.of(transition));
     }
 
-    /**
-     * Returns a mod loading state with state transition information and a custom human-friendly message function.
-     *
-     * @param name       the name of the state
-     * @param previous   the name of the immediately previous state to this state
-     * @param message    a function returning a human-friendly message for this state
-     * @param phase      the mod loading phase the state belongs to
-     * @param transition the state transition information
-     * @return a mod loading state with state transition information and a custom message
-     */
-    public static ModLoadingState withTransition(final String name, final String previous,
-                                                 final Function<ModList, String> message, final ModLoadingPhase phase,
-                                                 final IModStateTransition transition) {
+    public static ModLoadingState withTransition(final String name, final String previous, final Function<ModList, String> message, final ModLoadingPhase phase, IModStateTransition transition) {
         return new ModLoadingState(name, previous, message, phase, Optional.empty(), Optional.of(transition));
     }
-
-    /**
-     * Returns a mod loading state with an inline runnable and a default human-friendly message of {@code Processing
-     * work [name]}.
-     *
-     * @param name     the name of the state
-     * @param previous the name of the immediately previous state to this state
-     * @param phase    the mod loading phase the state belongs to
-     * @param inline   an optional runnable, which runs before starting the transition from this state to the next
-     * @return a mod loading state with an inline runnable and default message
-     */
-    public static ModLoadingState withInline(final String name, final String previous, final ModLoadingPhase phase,
-                                             final Consumer<ModList> inline) {
-        return new ModLoadingState(name, previous, ml -> "Processing work " + name, phase, Optional.of(inline), Optional.empty());
+    public static ModLoadingState withInline(final String name, final String previous, final ModLoadingPhase phase, Consumer<ModList> inline) {
+        return new ModLoadingState(name, previous, ml->"Processing work "+name, phase, Optional.of(inline), Optional.empty());
     }
 }

fmlcore/src/main/java/net/minecraftforge/fml/VersionChecker.java

@@ -117,14 +117,22 @@ public class VersionChecker
             /**
              * Returns the response body as a String for the given URL while following redirects
              */
-            private String openUrlString(URL url) throws IOException, URISyntaxException, InterruptedException {
+            private String openUrlString(URL url, IModInfo mod) throws IOException, URISyntaxException, InterruptedException {
                 URL currentUrl = url;
+
+                final StringBuilder sb = new StringBuilder();
+                sb.append("Java-http-client/").append(System.getProperty("java.version")).append(' ');
+                sb.append("MinecraftForge/").append(FMLLoader.versionInfo().mcAndForgeVersion()).append(' ');
+                sb.append(mod.getModId()).append('/').append(mod.getVersion());
+                final String userAgent = sb.toString();
+
                 for (int redirects = 0; redirects < MAX_HTTP_REDIRECTS; redirects++)
                 {
                     var request = HttpRequest.newBuilder()
                             .uri(currentUrl.toURI())
                             .timeout(Duration.ofSeconds(HTTP_TIMEOUT_SECS))
                             .setHeader("Accept-Encoding", "gzip")
+                            .setHeader("User-Agent", userAgent)
                             .GET()
                             .build();
 
@@ -166,7 +174,7 @@ public class VersionChecker
                     URL url = mod.getUpdateURL().get();
                     LOGGER.info("[{}] Starting version check at {}", mod.getModId(), url.toString());
 
-                    String data = openUrlString(url);
+                    String data = openUrlString(url, mod);
 
                     LOGGER.debug("[{}] Received version check data:\n{}", mod.getModId(), data);
 

fmlcore/src/main/java/net/minecraftforge/fml/config/ConfigFileTypeHandler.java

@@ -10,11 +10,11 @@ import com.electronwill.nightconfig.core.file.CommentedFileConfig;
 import com.electronwill.nightconfig.core.file.FileWatcher;
 import com.electronwill.nightconfig.core.io.ParsingException;
 import com.electronwill.nightconfig.core.io.WritingMode;
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.FMLConfig;
 import net.minecraftforge.fml.loading.FMLPaths;
 import org.apache.commons.io.FilenameUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -24,7 +24,7 @@ import java.util.function.Function;
 import static net.minecraftforge.fml.config.ConfigTracker.CONFIG;
 
 public class ConfigFileTypeHandler {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     static ConfigFileTypeHandler TOML = new ConfigFileTypeHandler();
     private static final Path defaultConfigPath = FMLPaths.GAMEDIR.get().resolve(FMLConfig.defaultConfigPath());
 

fmlcore/src/main/java/net/minecraftforge/fml/config/ConfigTracker.java

@@ -7,18 +7,18 @@ package net.minecraftforge.fml.config;
 
 import com.electronwill.nightconfig.core.CommentedConfig;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
-import org.slf4j.Marker;
-import org.slf4j.MarkerFactory;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
 
 import java.nio.file.Path;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
 public class ConfigTracker {
-    private static final Logger LOGGER = LogUtils.getLogger();
-    static final Marker CONFIG = MarkerFactory.getMarker("CONFIG");
+    private static final Logger LOGGER = LogManager.getLogger();
+    static final Marker CONFIG = MarkerManager.getMarker("CONFIG");
     public static final ConfigTracker INSTANCE = new ConfigTracker();
     private final ConcurrentHashMap<String, ModConfig> fileMap;
     private final EnumMap<ModConfig.Type, Set<ModConfig>> configSets;

fmlloader/build.gradle

@@ -11,34 +11,32 @@ dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
 configurations.forEach{ it.transitive = false }
 
 dependencies {
-    compileOnly("org.jetbrains:annotations:${JETBRAINS_ANNOTATIONS_VERSION}")
-
+    implementation('net.sf.jopt-simple:jopt-simple:5.0.4')
+    compileOnly('org.jetbrains:annotations:23.0.0')
     api("org.ow2.asm:asm:${ASM_VERSION}")
     api("org.ow2.asm:asm-tree:${ASM_VERSION}")
     api("org.ow2.asm:asm-commons:${ASM_VERSION}")
     api("net.minecraftforge:forgespi:${SPI_VERSION}")
-    api("org.apache.logging.log4j:log4j-api:${LOG4J_VERSION}")
-    api("org.slf4j:slf4j-api:${SLF4J_API_VERSION}")
-    api("com.google.guava:guava:${GUAVA_VERSION}")
-    api("com.google.code.gson:gson:${GSON_VERSION}")
-    api("org.apache.maven:maven-artifact:${APACHE_MAVEN_ARTIFACT_VERSION}")
-    api("org.apache.commons:commons-lang3:${APACHE_COMMONS_LANG3_VERSION}")
-    api("com.electronwill.night-config:core:${NIGHTCONFIG_VERSION}")
-    api("com.electronwill.night-config:toml:${NIGHTCONFIG_VERSION}")
-    api("cpw.mods:modlauncher:${MODLAUNCHER_VERSION}")
-    api("net.minecraftforge:coremods:${COREMODS_VERSION}")
-    api("com.mojang:logging:${MOJANG_LOGGING_VERSION}")
+    api('org.apache.logging.log4j:log4j-api:2.17.0')
+    api('org.slf4j:slf4j-api:1.8.0-beta4')
+    api('com.google.guava:guava:21.0')
+    api('com.google.code.gson:gson:2.8.9')
+    api('org.apache.maven:maven-artifact:3.8.1')
+    api('org.apache.commons:commons-lang3:3.12.0')
+    api('com.electronwill.night-config:core:3.6.4')
+    api('com.electronwill.night-config:toml:3.6.4')
+    api('cpw.mods:modlauncher:9.0.+')
+    api('net.minecraftforge:coremods:5.0.+')
+    api "net.minecraftforge:JarJarSelector:${JARJAR_VERSION}"
+    api "net.minecraftforge:JarJarMetadata:${JARJAR_VERSION}"
 
-    implementation("net.sf.jopt-simple:jopt-simple:${JOPT_SIMPLE_VERSION}")
     implementation("cpw.mods:securejarhandler:${SECUREJARHANDLER_VERSION}")
-    implementation("net.minecraftforge:accesstransformers:${ACCESSTRANSFORMERS_VERSION}")
-    implementation("net.minecrell:terminalconsoleappender:${TERMINALCONSOLEAPPENDER_VERSION}")
-    // implementation("org.jline:jline:${JLINE_VERSION}")
-
-    implementation("org.apache.logging.log4j:log4j-core:${LOG4J_VERSION}")
-    annotationProcessor("org.apache.logging.log4j:log4j-core:${LOG4J_VERSION}")
-
-    testCompileOnly("org.jetbrains:annotations:${JETBRAINS_ANNOTATIONS_VERSION}")
+    implementation('org.apache.logging.log4j:log4j-core:2.17.0')
+    annotationProcessor('org.apache.logging.log4j:log4j-core:2.17.0')
+    implementation('net.minecraftforge:accesstransformers:8.0.4')
+    implementation('net.minecrell:terminalconsoleappender:1.2.0')
+//    implementation('org.jline:jline:3.12.+')
+    testCompileOnly('org.jetbrains:annotations:21.0.0')
     testRuntimeOnly("cpw.mods:bootstraplauncher:${BOOTSTRAPLAUNCHER_VERSION}")
 }
 

fmlloader/src/main/java/net/minecraftforge/fml/common/asm/ObjectHolderDefinalize.java

@@ -7,11 +7,7 @@ package net.minecraftforge.fml.common.asm;
 
 import java.util.EnumSet;
 import java.util.List;
-import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
@@ -24,17 +20,7 @@ import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
  * Will also de-finalize all fields in on class level annotations.
  */
 public class ObjectHolderDefinalize implements ILaunchPluginService {
-    // Hardcoded map of vanilla classes that should have object holders for each field of the given registry type.
-    // IMPORTANT: Updates to this collection must be reflected in ObjectHolderRegistry. Duplicated cuz classloaders, yay!
-    // Classnames are validated in ObjectHolderRegistry.
-    private static final Map<String, VanillaObjectHolderData> VANILLA_OBJECT_HOLDERS = Stream.of(
-            new VanillaObjectHolderData("net.minecraft.world.level.block.Blocks", "block", "net.minecraft.world.level.block.Block"),
-            new VanillaObjectHolderData("net.minecraft.world.item.Items", "item", "net.minecraft.world.item.Item"),
-            new VanillaObjectHolderData("net.minecraft.world.item.enchantment.Enchantments", "enchantment", "net.minecraft.world.item.enchantment.Enchantment"),
-            new VanillaObjectHolderData("net.minecraft.world.effect.MobEffects", "mob_effect", "net.minecraft.world.effect.MobEffect"),
-            new VanillaObjectHolderData("net.minecraft.core.particles.ParticleTypes", "particle_type", "net.minecraft.core.particles.ParticleType"),
-            new VanillaObjectHolderData("net.minecraft.sounds.SoundEvents", "sound_event", "net.minecraft.sounds.SoundEvent")
-    ).collect(Collectors.toMap(VanillaObjectHolderData::holderClass, Function.identity()));
+
     private final String OBJECT_HOLDER = "Lnet/minecraftforge/registries/ObjectHolder;"; //Don't directly reference this to prevent class loading.
 
     @Override
@@ -42,6 +28,7 @@ public class ObjectHolderDefinalize implements ILaunchPluginService {
         return "object_holder_definalize";
     }
 
+
     private static final EnumSet<Phase> YAY = EnumSet.of(Phase.AFTER);
     private static final EnumSet<Phase> NAY = EnumSet.noneOf(Phase.class);
 
@@ -86,8 +73,10 @@ public class ObjectHolderDefinalize implements ILaunchPluginService {
             changes.compareAndSet(false, prev != f.access);
         });
 
-        if (VANILLA_OBJECT_HOLDERS.containsKey(classType.getClassName())) //Class level, de-finalize all fields and add @ObjectHolder to them!
+        if (hasHolder(classNode.visibleAnnotations)) //Class level, de-finalize all fields and add @ObjectHolder to them!
         {
+            @SuppressWarnings("unused")
+            String value = getValue(classNode.visibleAnnotations);
             classNode.fields.stream().filter(f -> ((f.access & flags) == flags) && f.desc.startsWith("L")).forEach(f ->
             {
                 int prev = f.access;
@@ -106,5 +95,4 @@ public class ObjectHolderDefinalize implements ILaunchPluginService {
         return changes.get() ? ComputeFlags.SIMPLE_REWRITE : ComputeFlags.NO_REWRITE;
     }
 
-    private record VanillaObjectHolderData(String holderClass, String registryName, String registryType) {}
 }

fmlloader/src/main/java/net/minecraftforge/fml/common/asm/RuntimeEnumExtender.java

@@ -9,7 +9,9 @@ import java.util.EnumSet;
 import java.util.List;
 import java.util.stream.Collectors;
 
-import com.mojang.logging.LogUtils;
+import net.minecraftforge.fml.loading.AdvancedLogMessageAdapter;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.objectweb.asm.Label;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
@@ -19,9 +21,6 @@ import org.objectweb.asm.tree.FieldNode;
 import org.objectweb.asm.tree.MethodNode;
 
 import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
-import org.slf4j.Logger;
-import org.slf4j.Marker;
-import org.slf4j.MarkerFactory;
 
 /**
  * Modifies specified enums to allow runtime extension by making the $VALUES field non-final and
@@ -29,7 +28,7 @@ import org.slf4j.MarkerFactory;
  */
 public class RuntimeEnumExtender implements ILaunchPluginService {
 
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final Type STRING = Type.getType(String.class);
     private final Type ENUM = Type.getType(Enum.class);
     private final Type MARKER_IFACE = Type.getType("Lnet/minecraftforge/common/IExtensibleEnum;");
@@ -64,49 +63,43 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
         final int flags = Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL | Opcodes.ACC_SYNTHETIC;
 
         FieldNode values = classNode.fields.stream().filter(f -> f.desc.contentEquals(array.getDescriptor()) && ((f.access & flags) == flags)).findFirst().orElse(null);
-
+        
         if (!classNode.interfaces.contains(MARKER_IFACE.getInternalName())) {
             return ComputeFlags.NO_REWRITE;
         }
-
+        
         //Static methods named "create" with first argument as a string
         List<MethodNode> candidates = classNode.methods.stream()
                 .filter(m -> ((m.access & Opcodes.ACC_STATIC) != 0) && m.name.equals("create"))
                 .collect(Collectors.toList());
-
+        
         if (candidates.isEmpty()) {
             throw new IllegalStateException("IExtensibleEnum has no candidate factory methods: " + classType.getClassName());
         }
-
+        
         candidates.forEach(mtd ->
         {
             Type[] args = Type.getArgumentTypes(mtd.desc);
             if (args.length == 0 || !args[0].equals(STRING)) {
-                if (LOGGER.isErrorEnabled(LogUtils.FATAL_MARKER))
-                {
-                    StringBuilder sb = new StringBuilder();
+                LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method without String as first parameter:\n");
                     sb.append("  Enum: ").append(classType.getDescriptor()).append("\n");
                     sb.append("  Target: ").append(mtd.name).append(mtd.desc).append("\n");
-                    LOGGER.error(LogUtils.FATAL_MARKER, sb.toString());
-                }
+                }));
                 throw new IllegalStateException("Enum has create method without String as first parameter: " + mtd.name + mtd.desc);
             }
 
             Type ret = Type.getReturnType(mtd.desc);
             if (!ret.equals(classType)) {
-                if (LOGGER.isErrorEnabled(LogUtils.FATAL_MARKER))
-                {
-                    StringBuilder sb = new StringBuilder();
+                LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method with incorrect return type:\n");
                     sb.append("  Enum: ").append(classType.getDescriptor()).append("\n");
                     sb.append("  Target: ").append(mtd.name).append(mtd.desc).append("\n");
                     sb.append("  Found: ").append(ret.getClassName()).append(", Expected: ").append(classType.getClassName());
-                    LOGGER.error(LogUtils.FATAL_MARKER, sb.toString());
-                }
+                }));
                 throw new IllegalStateException("Enum has create method with incorrect return type: " + mtd.name + mtd.desc);
             }
-
+            
             Type[] ctrArgs = new Type[args.length + 1];
             ctrArgs[0] = STRING;
             ctrArgs[1] = Type.INT_TYPE;
@@ -118,29 +111,23 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
             MethodNode ctr = classNode.methods.stream().filter(m -> m.name.equals("<init>") && m.desc.equals(desc)).findFirst().orElse(null);
             if (ctr == null)
             {
-                if (LOGGER.isErrorEnabled(LogUtils.FATAL_MARKER))
-                {
-                    StringBuilder sb = new StringBuilder();
+                LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method with no matching constructor:\n");
                     sb.append("  Enum: ").append(classType.getDescriptor()).append("\n");
                     sb.append("  Candidate: ").append(mtd.desc).append("\n");
                     sb.append("  Target: ").append(desc).append("\n");
                     classNode.methods.stream().filter(m -> m.name.equals("<init>")).forEach(m -> sb.append("        : ").append(m.desc).append("\n"));
-                    LOGGER.error(LogUtils.FATAL_MARKER, sb.toString());
-                }
+                }));
                 throw new IllegalStateException("Enum has create method with no matching constructor: " + desc);
             }
 
             if (values == null)
             {
-                if (LOGGER.isErrorEnabled(LogUtils.FATAL_MARKER))
-                {
-                    StringBuilder sb = new StringBuilder();
+                LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method but we could not find $VALUES. Found:\n");
                     classNode.fields.stream().filter(f -> (f.access & Opcodes.ACC_STATIC) != 0).
                             forEach(m -> sb.append("  ").append(m.name).append(" ").append(m.desc).append("\n"));
-                    LOGGER.error(LogUtils.FATAL_MARKER, sb.toString());
-                }
+                }));
                 throw new IllegalStateException("Enum has create method but we could not find $VALUES");
             }
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/AdvancedLogMessageAdapter.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading;
+
+import org.apache.logging.log4j.message.Message;
+import org.apache.logging.log4j.util.StringBuilderFormattable;
+
+import java.util.function.Consumer;
+
+public class AdvancedLogMessageAdapter implements Message, StringBuilderFormattable {
+    private static final long serialVersionUID = -8291754833965087436L;
+
+    private static final Object[] EMPTY = new Object[0];
+
+    private final Consumer<StringBuilder> logMessageBuilder;
+
+    public AdvancedLogMessageAdapter(final Consumer<StringBuilder> logMessageBuilder) {
+        this.logMessageBuilder = logMessageBuilder;
+    }
+
+    @Override
+    public String getFormattedMessage() {
+        return "";
+    }
+
+    @Override
+    public String getFormat() {
+        return "";
+    }
+
+    @Override
+    public Object[] getParameters() {
+        return EMPTY;
+    }
+
+    @Override
+    public Throwable getThrowable() {
+        return null;
+    }
+
+    @Override
+    public void formatTo(final StringBuilder buffer) {
+        logMessageBuilder.accept(buffer);
+    }
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/ClasspathLocatorUtils.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class ClasspathLocatorUtils {
+    
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    public static Path findJarPathFor(final String resourceName, final String jarName, final URL resource) {
+        try {
+            Path path;
+            final URI uri = resource.toURI();
+            if (uri.getScheme().equals("jar") && uri.getRawSchemeSpecificPart().contains("!/")) {
+                int lastExcl = uri.getRawSchemeSpecificPart().lastIndexOf("!/");
+                path = Paths.get(new URI(uri.getRawSchemeSpecificPart().substring(0, lastExcl)));
+            } else {
+                path = Paths.get(new URI("file://"+uri.getRawSchemeSpecificPart().substring(0, uri.getRawSchemeSpecificPart().length()-resourceName.length())));
+            }
+            //LOGGER.debug(CORE, "Found JAR {} at path {}", jarName, path.toString());
+            return path;
+        } catch (NullPointerException | URISyntaxException e) {
+            LOGGER.fatal(LogMarkers.SCAN, "Failed to find JAR for class {} - {}", resourceName, jarName);
+            throw new RuntimeException("Unable to locate "+resourceName+" - "+jarName, e);
+        }
+    }
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/ClasspathTransformerDiscoverer.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading;
+
+import cpw.mods.modlauncher.api.NamedPath;
+import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
+import org.apache.logging.log4j.LogManager;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.*;
+
+public class ClasspathTransformerDiscoverer implements ITransformerDiscoveryService {
+
+    private final List<Path> legacyClasspath = Arrays.stream(System.getProperty("legacyClassPath", "").split(File.pathSeparator)).map(Path::of).toList();
+
+    @Override
+    public List<NamedPath> candidates(Path gameDirectory) {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public List<NamedPath> candidates(final Path gameDirectory, final String launchTarget) {
+        if (launchTarget != null && launchTarget.contains("dev")) {
+            this.scan(gameDirectory);
+        }
+        return List.copyOf(found);
+    }
+
+    private final static List<NamedPath> found = new ArrayList<>();
+
+    public static List<Path> allExcluded() {
+        return found.stream().map(np->np.paths()[0]).toList();
+    }
+    
+    private void scan(final Path gameDirectory) {
+        try {
+            locateTransformers("META-INF/services/cpw.mods.modlauncher.api.ITransformationService");
+            locateTransformers("META-INF/services/net.minecraftforge.forgespi.locating.IModLocator");
+        } catch (IOException e) {
+            LogManager.getLogger().error("Error during discovery of transform services from the classpath", e);
+        }
+    }
+
+    private void locateTransformers(String resource) throws IOException {
+        final Enumeration<URL> resources = ClassLoader.getSystemClassLoader().getResources(resource);
+        while (resources.hasMoreElements()) {
+            URL url = resources.nextElement();
+            Path path = ClasspathLocatorUtils.findJarPathFor(resource, url.toString(), url);
+            if (legacyClasspath.stream().anyMatch(path::equals) || !Files.exists(path) || Files.isDirectory(path))
+                continue;
+            found.add(new NamedPath(path.toUri().toString(), path));
+        }
+    }
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/EarlyLoadingException.java

@@ -47,7 +47,7 @@ public class EarlyLoadingException extends RuntimeException {
         return errorMessages;
     }
 
-    EarlyLoadingException(final String message, final Throwable originalException, List<ExceptionData> errorMessages) {
+    public EarlyLoadingException(final String message, final Throwable originalException, List<ExceptionData> errorMessages) {
         super(message, originalException);
         this.errorMessages = errorMessages;
     }

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLConfig.java

@@ -10,8 +10,8 @@ import com.electronwill.nightconfig.core.file.CommentedFileConfig;
 import com.electronwill.nightconfig.core.file.FileNotFoundAction;
 import com.electronwill.nightconfig.core.io.ParsingException;
 import com.electronwill.nightconfig.core.io.WritingMode;
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -21,7 +21,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class FMLConfig
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private static FMLConfig INSTANCE = new FMLConfig();
     private static ConfigSpec configSpec = new ConfigSpec();
     static {
@@ -60,14 +60,11 @@ public class FMLConfig
     {
         final Path configFile = FMLPaths.FMLCONFIG.get();
         INSTANCE.loadFrom(configFile);
-        if (LOGGER.isTraceEnabled(CORE))
-        {
-            LOGGER.trace(CORE, "Loaded FML config from {}", FMLPaths.FMLCONFIG.get());
-            LOGGER.trace(CORE, "Splash screen is {}", FMLConfig.splashScreenEnabled());
-            LOGGER.trace(CORE, "Max threads for mod loading computed at {}", FMLConfig.loadingThreadCount());
-            LOGGER.trace(CORE, "Version check is {}", FMLConfig.runVersionCheck());
-            LOGGER.trace(CORE, "Default config paths at {}", FMLConfig.defaultConfigPath());
-        }
+        LOGGER.trace(CORE, "Loaded FML config from {}", FMLPaths.FMLCONFIG.get());
+        LOGGER.trace(CORE, "Splash screen is {}", FMLConfig::splashScreenEnabled);
+        LOGGER.trace(CORE, "Max threads for mod loading computed at {}", FMLConfig::loadingThreadCount);
+        LOGGER.trace(CORE, "Version check is {}", FMLConfig::runVersionCheck);
+        LOGGER.trace(CORE, "Default config paths at {}", FMLConfig::defaultConfigPath);
         FMLPaths.getOrCreateGameRelativePath(Paths.get(FMLConfig.defaultConfigPath()), "default config directory");
     }
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLLoader.java

@@ -5,7 +5,6 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.Launcher;
 import cpw.mods.modlauncher.api.*;
 import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
@@ -22,7 +21,8 @@ import net.minecraftforge.fml.loading.targets.CommonLaunchHandler;
 import net.minecraftforge.forgespi.Environment;
 import net.minecraftforge.forgespi.coremod.ICoreModProvider;
 import org.apache.commons.lang3.tuple.Pair;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -35,7 +35,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.SCAN;
 
 public class FMLLoader
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private static AccessTransformerService accessTransformer;
     private static ModDiscoverer modDiscoverer;
     private static ICoreModProvider coreModProvider;
@@ -62,47 +62,50 @@ public class FMLLoader
         final Package modLauncherPackage = ITransformationService.class.getPackage();
         LOGGER.debug(CORE,"FML found ModLauncher version : {}", modLauncherPackage.getImplementationVersion());
         if (!modLauncherPackage.isCompatibleWith("4.0")) {
-            LOGGER.error(CORE, "Found incompatible ModLauncher specification : {}, version {} from {}", modLauncherPackage.getSpecificationVersion(), modLauncherPackage.getImplementationVersion(), modLauncherPackage.getImplementationVendor());
+            LOGGER.fatal(CORE,"Found incompatible ModLauncher specification : {}, version {} from {}", modLauncherPackage.getSpecificationVersion(), modLauncherPackage.getImplementationVersion(), modLauncherPackage.getImplementationVendor());
             throw new IncompatibleEnvironmentException("Incompatible modlauncher found "+modLauncherPackage.getSpecificationVersion());
         }
 
+        // Allows us to communicate properties with other services through ModLauncher
+        setupBlackboardKeys();
+
         accessTransformer = (AccessTransformerService) environment.findLaunchPlugin("accesstransformer").orElseThrow(()-> {
-            LOGGER.error(CORE, "Access Transformer library is missing, we need this to run");
+            LOGGER.fatal(CORE,"Access Transformer library is missing, we need this to run");
             return new IncompatibleEnvironmentException("Missing AccessTransformer, cannot run");
         });
 
         final Package atPackage = accessTransformer.getClass().getPackage();
         LOGGER.debug(CORE,"FML found AccessTransformer version : {}", atPackage.getImplementationVersion());
         if (!atPackage.isCompatibleWith("1.0")) {
-            LOGGER.error(CORE, "Found incompatible AccessTransformer specification : {}, version {} from {}", atPackage.getSpecificationVersion(), atPackage.getImplementationVersion(), atPackage.getImplementationVendor());
+            LOGGER.fatal(CORE,"Found incompatible AccessTransformer specification : {}, version {} from {}", atPackage.getSpecificationVersion(), atPackage.getImplementationVersion(), atPackage.getImplementationVendor());
             throw new IncompatibleEnvironmentException("Incompatible accesstransformer found "+atPackage.getSpecificationVersion());
         }
 
         eventBus = environment.findLaunchPlugin("eventbus").orElseThrow(()-> {
-            LOGGER.error(CORE, "Event Bus library is missing, we need this to run");
+            LOGGER.fatal(CORE,"Event Bus library is missing, we need this to run");
             return new IncompatibleEnvironmentException("Missing EventBus, cannot run");
         });
 
         final Package eventBusPackage = eventBus.getClass().getPackage();
         LOGGER.debug(CORE,"FML found EventBus version : {}", eventBusPackage.getImplementationVersion());
         if (!eventBusPackage.isCompatibleWith("1.0")) {
-            LOGGER.error(CORE, "Found incompatible EventBus specification : {}, version {} from {}", eventBusPackage.getSpecificationVersion(), eventBusPackage.getImplementationVersion(), eventBusPackage.getImplementationVendor());
+            LOGGER.fatal(CORE,"Found incompatible EventBus specification : {}, version {} from {}", eventBusPackage.getSpecificationVersion(), eventBusPackage.getImplementationVersion(), eventBusPackage.getImplementationVendor());
             throw new IncompatibleEnvironmentException("Incompatible eventbus found "+eventBusPackage.getSpecificationVersion());
         }
 
         runtimeDistCleaner = (RuntimeDistCleaner)environment.findLaunchPlugin("runtimedistcleaner").orElseThrow(()-> {
-            LOGGER.error(CORE, "Dist Cleaner is missing, we need this to run");
+            LOGGER.fatal(CORE,"Dist Cleaner is missing, we need this to run");
             return new IncompatibleEnvironmentException("Missing DistCleaner, cannot run!");
         });
         LOGGER.debug(CORE, "Found Runtime Dist Cleaner");
 
-        var coreModProviders = ServiceLoaderUtils.streamWithErrorHandling(ServiceLoader.load(FMLLoader.class.getModule().getLayer(), ICoreModProvider.class), sce -> LOGGER.error(CORE, "Failed to load a coremod library, expect problems", sce)).toList();
+        var coreModProviders = ServiceLoaderUtils.streamWithErrorHandling(ServiceLoader.load(FMLLoader.class.getModule().getLayer(), ICoreModProvider.class), sce -> LOGGER.fatal(CORE, "Failed to load a coremod library, expect problems", sce)).toList();
 
         if (coreModProviders.isEmpty()) {
-            LOGGER.error(CORE, "Found no coremod provider. Cannot run");
+            LOGGER.fatal(CORE, "Found no coremod provider. Cannot run");
             throw new IncompatibleEnvironmentException("No coremod library found");
         } else if (coreModProviders.size() > 1) {
-            LOGGER.error(CORE, "Found multiple coremod providers : {}. Cannot run", coreModProviders.stream().map(p -> p.getClass().getName()).collect(Collectors.toList()));
+            LOGGER.fatal(CORE, "Found multiple coremod providers : {}. Cannot run", coreModProviders.stream().map(p -> p.getClass().getName()).collect(Collectors.toList()));
             throw new IncompatibleEnvironmentException("Multiple coremod libraries found");
         }
 
@@ -114,7 +117,7 @@ public class FMLLoader
         LOGGER.debug(CORE, "Found ForgeSPI package implementation version {}", Environment.class.getPackage().getImplementationVersion());
         LOGGER.debug(CORE, "Found ForgeSPI package specification {}", Environment.class.getPackage().getSpecificationVersion());
         if (Integer.parseInt(Environment.class.getPackage().getSpecificationVersion()) < 2) {
-            LOGGER.error(CORE, "Found an out of date ForgeSPI implementation: {}, loading cannot continue", Environment.class.getPackage().getSpecificationVersion());
+            LOGGER.fatal(CORE, "Found an out of date ForgeSPI implementation: {}, loading cannot continue", Environment.class.getPackage().getSpecificationVersion());
             throw new IncompatibleEnvironmentException("ForgeSPI is out of date, we cannot continue");
         }
 
@@ -122,11 +125,17 @@ public class FMLLoader
             Class.forName("com.electronwill.nightconfig.core.Config", false, environment.getClass().getClassLoader());
             Class.forName("com.electronwill.nightconfig.toml.TomlFormat", false, environment.getClass().getClassLoader());
         } catch (ClassNotFoundException e) {
-            LOGGER.error(CORE, "Failed to load NightConfig");
+            LOGGER.fatal(CORE, "Failed to load NightConfig");
             throw new IncompatibleEnvironmentException("Missing NightConfig");
         }
     }
 
+    private static void setupBlackboardKeys() {
+        LOGGER.debug(CORE, "Requesting CoreMods to not apply the fix for ASMAPI.findFirstInstructionBefore by default");
+        var blackboardKey = TypesafeMap.Key.getOrCreate(Launcher.INSTANCE.blackboard(), "coremods.use_old_findFirstInstructionBefore", Boolean.class);
+        Launcher.INSTANCE.blackboard().<Boolean>computeIfAbsent(blackboardKey, k -> true);
+    }
+
     static void setupLaunchHandler(final IEnvironment environment, final Map<String, Object> arguments)
     {
         final String launchTarget = environment.getProperty(IEnvironment.Keys.LAUNCHTARGET.get()).orElse("MISSING");
@@ -134,12 +143,12 @@ public class FMLLoader
         final Optional<ILaunchHandlerService> launchHandler = environment.findLaunchHandler(launchTarget);
         LOGGER.debug(CORE, "Using {} as launch service", launchTarget);
         if (launchHandler.isEmpty()) {
-            LOGGER.error(CORE, "Missing LaunchHandler {}, cannot continue", launchTarget);
+            LOGGER.fatal(CORE,"Missing LaunchHandler {}, cannot continue", launchTarget);
             throw new RuntimeException("Missing launch handler: " + launchTarget);
         }
 
         if (!(launchHandler.get() instanceof CommonLaunchHandler)) {
-            LOGGER.error(CORE, "Incompatible Launch handler found - type {}, cannot continue", launchHandler.get().getClass().getName());
+            LOGGER.fatal(CORE, "Incompatible Launch handler found - type {}, cannot continue", launchHandler.get().getClass().getName());
             throw new RuntimeException("Incompatible launch handler found");
         }
         commonLaunchHandler = (CommonLaunchHandler)launchHandler.get();

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLPaths.java

@@ -5,9 +5,9 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.IEnvironment;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -22,7 +22,7 @@ public enum FMLPaths
     CONFIGDIR("config"),
     FMLCONFIG(false, CONFIGDIR, "fml.toml");
 
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final Path relativePath;
     private final boolean isDirectory;
     private Path absolutePath;
@@ -61,10 +61,7 @@ public enum FMLPaths
             {
                 FileUtils.getOrCreateDirectory(path.absolutePath, path.name());
             }
-            if (LOGGER.isDebugEnabled(CORE))
-            {
-                LOGGER.debug(CORE, "Path {} is {}", path, path.absolutePath);
-            }
+            LOGGER.debug(CORE,"Path {} is {}", ()-> path, ()-> path.absolutePath);
         }
     }
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLServiceProvider.java

@@ -5,14 +5,14 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.*;
 import joptsimple.ArgumentAcceptingOptionSpec;
 import joptsimple.OptionSpecBuilder;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.forgespi.Environment;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
-import org.slf4j.Logger;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -26,7 +26,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class FMLServiceProvider implements ITransformationService
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private ArgumentAcceptingOptionSpec<String> modsOption;
     private ArgumentAcceptingOptionSpec<String> modListsOption;
     private ArgumentAcceptingOptionSpec<String> mavenRootsOption;

fmlloader/src/main/java/net/minecraftforge/fml/loading/FileUtils.java

@@ -5,8 +5,8 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.nio.file.FileAlreadyExistsException;
@@ -17,7 +17,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class FileUtils
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
 
     public static Path getOrCreateDirectory(Path dirPath, String dirLabel) {
         if (!Files.isDirectory(dirPath.getParent())) {
@@ -25,20 +25,20 @@ public class FileUtils
         }
         if (!Files.isDirectory(dirPath))
         {
-            LOGGER.debug(CORE, "Making {} directory : {}", dirLabel, dirPath);
+            LOGGER.debug(CORE,"Making {} directory : {}", dirLabel, dirPath);
             try {
                 Files.createDirectory(dirPath);
             } catch (IOException e) {
                 if (e instanceof FileAlreadyExistsException) {
-                    LOGGER.error(CORE, "Failed to create {} directory - there is a file in the way", dirLabel);
+                    LOGGER.fatal(CORE,"Failed to create {} directory - there is a file in the way", dirLabel);
                 } else {
-                    LOGGER.error(CORE, "Problem with creating {} directory (Permissions?)", dirLabel, e);
+                    LOGGER.fatal(CORE,"Problem with creating {} directory (Permissions?)", dirLabel, e);
                 }
                 throw new RuntimeException("Problem creating directory", e);
             }
-            LOGGER.debug(CORE, "Created {} directory : {}", dirLabel, dirPath);
+            LOGGER.debug(CORE,"Created {} directory : {}", dirLabel, dirPath);
         } else {
-            LOGGER.debug(CORE, "Found existing {} directory : {}", dirLabel, dirPath);
+            LOGGER.debug(CORE,"Found existing {} directory : {}", dirLabel, dirPath);
         }
         return dirPath;
     }

fmlloader/src/main/java/net/minecraftforge/fml/loading/LanguageLoadingProvider.java

@@ -5,7 +5,6 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.Launcher;
 import cpw.mods.modlauncher.api.IModuleLayerManager;
 import cpw.mods.modlauncher.util.ServiceLoaderUtils;
@@ -13,10 +12,11 @@ import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
 import net.minecraftforge.fml.loading.moddiscovery.ExplodedDirectoryLocator;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 import org.apache.maven.artifact.versioning.VersionRange;
-import org.slf4j.Logger;
 
 import java.net.URISyntaxException;
 import java.nio.file.Files;
@@ -38,7 +38,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
 
 public class LanguageLoadingProvider
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final List<IModLanguageProvider> languageProviders = new ArrayList<>();
     private final ServiceLoader<IModLanguageProvider> serviceLoader;
     private final Map<String, ModLanguageWrapper> languageProviderMap = new HashMap<>();
@@ -81,7 +81,7 @@ public class LanguageLoadingProvider
         loadLanguageProviders();
     }
     private void loadLanguageProviders() {
-        LOGGER.debug(CORE, "Found {} language providers", ServiceLoaderUtils.streamServiceLoader(()->serviceLoader, sce->LOGGER.error("Problem with language loaders")).count());
+        LOGGER.debug(CORE, "Found {} language providers", ServiceLoaderUtils.streamServiceLoader(()->serviceLoader, sce->LOGGER.fatal("Problem with language loaders")).count());
         serviceLoader.forEach(languageProviders::add);
 
         languageProviders.forEach(lp -> {
@@ -94,7 +94,7 @@ public class LanguageLoadingProvider
             Optional<String> implementationVersion = JarVersionLookupHandler.getImplementationVersion(lp.getClass());
             String impl = implementationVersion.orElse(Files.isDirectory(lpPath) ? FMLLoader.versionInfo().forgeVersion().split("\\.")[0] : null);
             if (impl == null) {
-                LOGGER.error(CORE, "Found unversioned language provider {}", lp.name());
+                LOGGER.fatal(CORE, "Found unversioned language provider {}", lp.name());
                 throw new RuntimeException("Failed to find implementation version for language provider "+ lp.name());
             }
             LOGGER.debug(CORE, "Found language provider {}, version {}", lp.name(), impl);

fmlloader/src/main/java/net/minecraftforge/fml/loading/LauncherVersion.java

@@ -5,13 +5,13 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class LauncherVersion {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private static final String launcherVersion;
 
     static {

fmlloader/src/main/java/net/minecraftforge/fml/loading/LibraryFinder.java

@@ -5,14 +5,14 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
 
 public class LibraryFinder {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private static Path libsPath;
     static Path findLibsPath() {
         if (libsPath == null) {

fmlloader/src/main/java/net/minecraftforge/fml/loading/LogMarkers.java

@@ -5,12 +5,12 @@
 
 package net.minecraftforge.fml.loading;
 
-import org.slf4j.Marker;
-import org.slf4j.MarkerFactory;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
 
 public class LogMarkers {
-    public static final Marker CORE = MarkerFactory.getMarker("CORE");
-    public static final Marker LOADING = MarkerFactory.getMarker("LOADING");
-    public static final Marker SCAN = MarkerFactory.getMarker("SCAN");
-    public static final Marker SPLASH = MarkerFactory.getMarker("SPLASH");
+    public static final Marker CORE = MarkerManager.getMarker("CORE");
+    public static final Marker LOADING = MarkerManager.getMarker("LOADING");
+    public static final Marker SCAN = MarkerManager.getMarker("SCAN");
+    public static final Marker SPLASH = MarkerManager.getMarker("SPLASH");
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/MCPNamingService.java

@@ -5,10 +5,10 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.INameMappingService;
 import org.apache.commons.lang3.tuple.Pair;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -20,7 +20,7 @@ import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 
 public class MCPNamingService implements INameMappingService {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private HashMap<String, String> methods;
     private HashMap<String, String> fields;
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/ModDirTransformerDiscoverer.java

@@ -5,11 +5,10 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
 import cpw.mods.modlauncher.api.NamedPath;
 import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
 
 import java.io.File;
 import java.io.IOException;
@@ -20,8 +19,6 @@ import java.util.List;
 import java.util.zip.ZipFile;
 
 public class ModDirTransformerDiscoverer implements ITransformerDiscoveryService {
-    private static final Logger LOGGER = LogUtils.getLogger();
-
     @Override
     public List<NamedPath> candidates(final Path gameDirectory) {
         ModDirTransformerDiscoverer.scan(gameDirectory);
@@ -43,7 +40,7 @@ public class ModDirTransformerDiscoverer implements ITransformerDiscoveryService
         try (var walk = Files.walk(modsDir, 1)){
             walk.forEach(ModDirTransformerDiscoverer::visitFile);
         } catch (IOException | IllegalStateException ioe) {
-            LOGGER.error("Error during early discovery", ioe);
+            LogManager.getLogger().error("Error during early discovery", ioe);
         }
     }
 
@@ -58,7 +55,7 @@ public class ModDirTransformerDiscoverer implements ITransformerDiscoveryService
                 found.add(new NamedPath(zf.getName(), path));
             }
         } catch (IOException ioe) {
-            LOGGER.error("Zip Error when loading jar file {}", path, ioe);
+            LogManager.getLogger().error("Zip Error when loading jar file {}", path, ioe);
         }
     }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/ModJarURLHandler.java

@@ -5,9 +5,9 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -24,7 +24,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class ModJarURLHandler extends URLStreamHandler
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     // modjar://modid/path/to/file
     @Override
     protected URLConnection openConnection(URL url) {

fmlloader/src/main/java/net/minecraftforge/fml/loading/ModSorter.java

@@ -7,10 +7,8 @@ package net.minecraftforge.fml.loading;
 
 import com.google.common.graph.GraphBuilder;
 import com.google.common.graph.MutableGraph;
-import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.SecureJar;
 import net.minecraftforge.fml.loading.moddiscovery.MinecraftLocator;
-import net.minecraftforge.forgespi.language.IModFileInfo;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.fml.loading.EarlyLoadingException.ExceptionData;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
@@ -18,10 +16,10 @@ import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
 import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
 import net.minecraftforge.fml.loading.toposort.CyclePresentException;
 import net.minecraftforge.fml.loading.toposort.TopologicalSort;
-import net.minecraftforge.forgespi.locating.IModFile;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
-import org.slf4j.Logger;
 
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -35,15 +33,16 @@ import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
 
 public class ModSorter
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
+    private final UniqueModListBuilder uniqueModListBuilder;
     private List<ModFile> modFiles;
     private List<ModInfo> sortedList;
-    private Map<String, ModInfo> modIdNameLookup;
+    private Map<String, IModInfo> modIdNameLookup;
     private List<ModFile> systemMods;
 
     private ModSorter(final List<ModFile> modFiles)
     {
-        this.modFiles = modFiles;
+        this.uniqueModListBuilder = new UniqueModListBuilder(modFiles);
     }
 
     public static LoadingModList sort(List<ModFile> mods, final List<ExceptionData> errors)
@@ -78,11 +77,12 @@ public class ModSorter
         // lambdas are identity based, so sorting them is impossible unless you hold reference to them
         final MutableGraph<ModFileInfo> graph = GraphBuilder.directed().build();
         AtomicInteger counter = new AtomicInteger();
-        Map<IModFileInfo, Integer> infos = modFiles.stream()
+        Map<ModFileInfo, Integer> infos = modFiles.stream()
                 .map(ModFile::getModFileInfo)
                 .filter(ModFileInfo.class::isInstance)
+                .map(ModFileInfo.class::cast)
                 .collect(toMap(Function.identity(), e -> counter.incrementAndGet()));
-        infos.keySet().forEach(i -> graph.addNode((ModFileInfo) i));
+        infos.keySet().forEach(graph::addNode);
         modFiles.stream()
                 .map(ModFile::getModInfos)
                 .<IModInfo>mapMulti(Iterable::forEach)
@@ -98,10 +98,11 @@ public class ModSorter
         catch (CyclePresentException e)
         {
             Set<Set<ModFileInfo>> cycles = e.getCycles();
-            if (LOGGER.isErrorEnabled(LOADING))
-            {
-                LOGGER.error(LOADING, "Mod Sorting failed.\nDetected Cycles: {}\n", cycles);
-            }
+            LOGGER.error(LOADING, () -> new AdvancedLogMessageAdapter(buffer ->
+                    buffer.append("Mod Sorting failed.\n")
+                    .append("Detected Cycles: ")
+                    .append(cycles)
+                    .append('\n')));
             var dataList = cycles.stream()
                     .<ModFileInfo>mapMulti(Iterable::forEach)
                     .<IModInfo>mapMulti((mf,c)->mf.getMods().forEach(c))
@@ -124,10 +125,9 @@ public class ModSorter
     private void addDependency(MutableGraph<ModFileInfo> topoGraph, IModInfo.ModVersion dep)
     {
         final ModFileInfo self = (ModFileInfo)dep.getOwner().getOwningFile();
-        final ModInfo targetModInfo = modIdNameLookup.get(dep.getModId());
+        final IModInfo targetModInfo = modIdNameLookup.get(dep.getModId());
         // soft dep that doesn't exist. Just return. No edge required.
-        if (targetModInfo == null) return;
-        final ModFileInfo target = targetModInfo.getOwningFile();
+        if (targetModInfo == null || !(targetModInfo.getOwningFile() instanceof final ModFileInfo target)) return;
         if (self == target)
             return; // in case a jar has two mods that have dependencies between
         switch (dep.getOrdering()) {
@@ -138,10 +138,22 @@ public class ModSorter
 
     private void buildUniqueList()
     {
-        // Collect mod files by module name. This will be used for deduping purposes
-        final Map<String, List<IModFile>> modFilesByFirstId = modFiles.stream()
-                .collect(groupingBy(mf -> mf.getModFileInfo().moduleName()));
+        final UniqueModListBuilder.UniqueModListData uniqueModListData = uniqueModListBuilder.buildUniqueList();
 
+        this.modFiles = uniqueModListData.modFiles();
+
+        detectSystemMods(uniqueModListData.modFilesByFirstId());
+
+        modIdNameLookup = uniqueModListData.modFilesByFirstId().entrySet().stream()
+                .filter(e -> !e.getValue().get(0).getModInfos().isEmpty())
+                .collect(Collectors.toMap(
+                    Map.Entry::getKey,
+                    e -> e.getValue().get(0).getModInfos().get(0)
+                  ));
+    }
+
+    private void detectSystemMods(final Map<String, List<ModFile>> modFilesByFirstId)
+    {
         // Capture system mods (ex. MC, Forge) here, so we can keep them for later
         final Set<String> systemMods = new HashSet<>();
         // The minecraft mod is always a system mod
@@ -168,47 +180,6 @@ public class ModSorter
                 throw new IllegalStateException("Failed to find system mod: " + systemMod);
             }
         }
-
-        // Select the newest by artifact version sorting of non-unique files thus identified
-        this.modFiles = modFilesByFirstId.entrySet().stream()
-                .map(this::selectNewestModInfo)
-                .map(Map.Entry::getValue)
-                .map(ModFile.class::cast)
-                .collect(toList());
-
-        // Transform to the full mod id list
-        final Map<String, List<ModInfo>> modIds = modFiles.stream()
-                .map(ModFile::getModInfos)
-                .flatMap(Collection::stream)
-                .map(ModInfo.class::cast)
-                .collect(groupingBy(IModInfo::getModId));
-
-        // Its theoretically possible that some mod has somehow moved an id to a secondary place, thus causing a dupe.
-        // We can't handle this
-        final List<ModInfo> dupedMods = modIds.values().stream()
-                .filter(modInfos -> modInfos.size() > 1)
-                .map(modInfos -> modInfos.get(0))
-                .toList();
-
-        if (!dupedMods.isEmpty()) {
-            final List<EarlyLoadingException.ExceptionData> duplicateModErrors = dupedMods.stream()
-                    .map(dm -> new EarlyLoadingException.ExceptionData("fml.modloading.dupedmod",
-                            dm, Objects.toString(dm))).toList();
-            throw new EarlyLoadingException("Duplicate mods found", null,  duplicateModErrors);
-        }
-
-        modIdNameLookup = modIds.entrySet().stream()
-                .collect(toMap(Map.Entry::getKey, e -> e.getValue().get(0)));
-    }
-
-    private Map.Entry<String, IModFile> selectNewestModInfo(Map.Entry<String, List<IModFile>> fullList) {
-        List<IModFile> modInfoList = fullList.getValue();
-        if (modInfoList.size() > 1) {
-            LOGGER.debug("Found {} mods for first modid {}, selecting most recent based on version data", modInfoList.size(), fullList.getKey());
-            modInfoList.sort(Comparator.<IModFile, ArtifactVersion>comparing(mf -> mf.getModInfos().get(0).getVersion()).reversed());
-            LOGGER.debug("Selected file {} for modid {} with version {}", modInfoList.get(0).getFileName(), fullList.getKey(), modInfoList.get(0).getModInfos().get(0).getVersion());
-        }
-        return Map.entry(fullList.getKey(), modInfoList.get(0));
     }
 
     private List<EarlyLoadingException.ExceptionData> verifyDependencyVersions()
@@ -238,10 +209,24 @@ public class ModSorter
 
         if (!missingVersions.isEmpty()) {
             if (mandatoryMissing > 0) {
-                LOGGER.error(LOADING, "Missing mandatory dependencies: {}", missingVersions.stream().filter(IModInfo.ModVersion::isMandatory).map(IModInfo.ModVersion::getModId).collect(Collectors.joining(", ")));
+                LOGGER.error(
+                        LOADING,
+                        "Missing or unsupported mandatory dependencies:\n{}",
+                        missingVersions.stream()
+                                .filter(IModInfo.ModVersion::isMandatory)
+                                .map(ver -> formatDependencyError(ver, modVersions))
+                                .collect(Collectors.joining("\n"))
+                );
             }
             if (missingVersions.size() - mandatoryMissing > 0) {
-                LOGGER.error(LOADING, "Unsupported installed optional dependencies: {}", missingVersions.stream().filter(ver -> !ver.isMandatory()).map(IModInfo.ModVersion::getModId).collect(Collectors.joining(", ")));
+                LOGGER.error(
+                        LOADING,
+                        "Unsupported installed optional dependencies:\n{}",
+                        missingVersions.stream()
+                                .filter(ver -> !ver.isMandatory())
+                                .map(ver -> formatDependencyError(ver, modVersions))
+                                .collect(Collectors.joining("\n"))
+                );
             }
 
             return missingVersions.stream()
@@ -253,6 +238,18 @@ public class ModSorter
         return Collections.emptyList();
     }
 
+    private static String formatDependencyError(IModInfo.ModVersion dependency, Map<String, ArtifactVersion> modVersions)
+    {
+        ArtifactVersion installed = modVersions.get(dependency.getModId());
+        return String.format(
+                "\tMod ID: '%s', Requested by: '%s', Expected range: '%s', Actual version: '%s'",
+                dependency.getModId(),
+                dependency.getOwner().getModId(),
+                dependency.getVersionRange(),
+                installed != null ? installed.toString() : "[MISSING]"
+        );
+    }
+
     private boolean modVersionNotContained(final IModInfo.ModVersion mv, final Map<String, ArtifactVersion> modVersions)
     {
         return !(VersionSupportMatrix.testVersionSupportMatrix(mv.getVersionRange(), mv.getModId(), "mod", (modId, range) -> modVersions.containsKey(modId) &&

fmlloader/src/main/java/net/minecraftforge/fml/loading/RuntimeDistCleaner.java

@@ -16,11 +16,14 @@ import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 import com.google.common.collect.Streams;
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
 import net.minecraftforge.api.distmarker.OnlyIns;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.Marker;
+import org.apache.logging.log4j.MarkerManager;
 import org.objectweb.asm.Handle;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
@@ -30,14 +33,11 @@ import org.objectweb.asm.tree.AnnotationNode;
 import org.objectweb.asm.tree.ClassNode;
 import org.objectweb.asm.tree.FieldNode;
 import org.objectweb.asm.tree.MethodNode;
-import org.slf4j.Logger;
-import org.slf4j.Marker;
-import org.slf4j.MarkerFactory;
 
 public class RuntimeDistCleaner implements ILaunchPluginService
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
-    private static final Marker DISTXFORM = MarkerFactory.getMarker("DISTXFORM");
+    private static final Logger LOGGER = LogManager.getLogger();
+    private static final Marker DISTXFORM = MarkerManager.getMarker("DISTXFORM");
     private static String DIST;
     private static final String ONLYIN = Type.getDescriptor(OnlyIn.class);
     private static final String ONLYINS = Type.getDescriptor(OnlyIns.class);
@@ -53,7 +53,7 @@ public class RuntimeDistCleaner implements ILaunchPluginService
         AtomicBoolean changes = new AtomicBoolean();
         if (remove(classNode.visibleAnnotations, DIST))
         {
-            LOGGER.error(DISTXFORM, "Attempted to load class {} for invalid dist {}", classNode.name, DIST);
+            LOGGER.fatal(DISTXFORM, "Attempted to load class {} for invalid dist {}", classNode.name, DIST);
             throw new RuntimeException("Attempted to load class "+ classNode.name  + " for invalid dist "+ DIST);
         }
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/TracingPrintStream.java

@@ -5,7 +5,8 @@
 
 package net.minecraftforge.fml.loading;
 
-import org.slf4j.Logger;
+import org.apache.logging.log4j.Logger;
+
 import java.io.PrintStream;
 
 /**

fmlloader/src/main/java/net/minecraftforge/fml/loading/UniqueModListBuilder.java

@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading;
+
+import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import net.minecraftforge.forgespi.language.IModInfo;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+
+import java.util.*;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import static java.util.stream.Collectors.*;
+
+public class UniqueModListBuilder
+{
+    private final static Logger LOGGER = LogManager.getLogger();
+
+    private final List<ModFile> modFiles;
+
+    public UniqueModListBuilder(final List<ModFile> modFiles) {this.modFiles = modFiles;}
+
+    public UniqueModListData buildUniqueList()
+    {
+        List<ModFile> uniqueModList;
+        List<ModFile> uniqueLibListWithVersion;
+
+        // Collect mod files by module name. This will be used for deduping purposes
+        final Map<String, List<ModFile>> modFilesByFirstId = modFiles.stream()
+                .filter(mf -> mf.getModFileInfo() != null)
+                .collect(groupingBy(UniqueModListBuilder::getModId));
+
+        final Map<String, List<ModFile>> libFilesWithVersionByModuleName = modFiles.stream()
+                .filter(mf -> mf.getModFileInfo() == null)
+                .collect(groupingBy(UniqueModListBuilder::getModId));
+
+        // Select the newest by artifact version sorting of non-unique files thus identified
+        uniqueModList = modFilesByFirstId.entrySet().stream()
+                .map(this::selectNewestModInfo)
+                .toList();
+
+        // Select the newest by artifact version sorting of non-unique files thus identified
+        uniqueLibListWithVersion = libFilesWithVersionByModuleName.entrySet().stream()
+                .map(this::selectNewestModInfo)
+                .toList();
+
+        // Transform to the full mod id list
+        final Map<String, List<IModInfo>> modIds = uniqueModList.stream()
+                .filter(mf -> mf.getModFileInfo() != null) //Filter out non-mod files, we don't care about those for now.....
+                .map(ModFile::getModInfos)
+                .flatMap(Collection::stream)
+                .collect(groupingBy(IModInfo::getModId));
+
+        // Transform to the full lib id list
+        final Map<String, List<ModFile>> versionedLibIds = uniqueLibListWithVersion.stream()
+                .map(UniqueModListBuilder::getModId)
+                .collect(Collectors.toMap(
+                    Function.identity(),
+                    libFilesWithVersionByModuleName::get
+                ));
+
+        // Its theoretically possible that some mod has somehow moved an id to a secondary place, thus causing a dupe.
+        // We can't handle this
+        final List<IModInfo> dupedMods = modIds.values().stream()
+                .filter(modInfos -> modInfos.size() > 1)
+                .map(modInfos -> modInfos.get(0))
+                .toList();
+
+        if (!dupedMods.isEmpty()) {
+            final List<EarlyLoadingException.ExceptionData> duplicateModErrors = dupedMods.stream()
+                                                                                   .map(dm -> new EarlyLoadingException.ExceptionData("fml.modloading.dupedmod", dm, Objects.toString(dm)))
+                                                                                   .toList();
+            throw new EarlyLoadingException("Duplicate mods found", null,  duplicateModErrors);
+        }
+
+        final List<ModFile> dupedLibs = versionedLibIds.values().stream()
+                .filter(modFiles -> modFiles.size() > 1)
+                .map(modFiles -> modFiles.get(0))
+                .toList();
+
+        if (!dupedLibs.isEmpty()) {
+            final List<EarlyLoadingException.ExceptionData> duplicateLibErrors = dupedLibs.stream()
+                .map(dm -> new EarlyLoadingException.ExceptionData("fml.modloading.dupedlib.versioned", dm, Objects.toString(dm)))
+                .toList();
+            throw new EarlyLoadingException("Duplicate plugins or libraries found", null,  duplicateLibErrors);
+        }
+
+        // Collect unique mod files by module name. This will be used for deduping purposes
+        final Map<String, List<ModFile>> uniqueModFilesByFirstId = uniqueModList.stream()
+                .collect(groupingBy(UniqueModListBuilder::getModId));
+
+        final List<ModFile> loadedList = new ArrayList<>();
+        loadedList.addAll(uniqueModList);
+        loadedList.addAll(uniqueLibListWithVersion);
+
+        return new UniqueModListData(loadedList, uniqueModFilesByFirstId);
+    }
+
+    private ModFile selectNewestModInfo(Map.Entry<String, List<ModFile>> fullList) {
+        List<ModFile> modInfoList = fullList.getValue();
+        if (modInfoList.size() > 1) {
+            LOGGER.debug("Found {} mods for first modid {}, selecting most recent based on version data", modInfoList.size(), fullList.getKey());
+            modInfoList.sort(Comparator.comparing(this::getVersion).reversed());
+            LOGGER.debug("Selected file {} for modid {} with version {}", modInfoList.get(0).getFileName(), fullList.getKey(), modInfoList.get(0).getModInfos().get(0).getVersion());
+        }
+        return modInfoList.get(0);
+    }
+
+    private ArtifactVersion getVersion(final ModFile mf)
+    {
+        if (mf.getModFileInfo() == null) {
+            return mf.getJarVersion();
+        }
+        return mf.getModInfos().get(0).getVersion();
+    }
+
+    private static String getModId(ModFile modFile) {
+        if (modFile.getModFileInfo() == null || modFile.getModFileInfo().getMods().isEmpty()) {
+            return modFile.getSecureJar().name();
+        }
+
+        return modFile.getModFileInfo().moduleName();
+    }
+
+    public record UniqueModListData(List<ModFile> modFiles, Map<String, List<ModFile>> modFilesByFirstId) {}
+
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/AbstractJarFileDependencyLocator.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading.moddiscovery;
+
+import net.minecraftforge.forgespi.locating.IModFile;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+
+public abstract class AbstractJarFileDependencyLocator extends AbstractJarFileLocator
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    protected Optional<InputStream> loadResourceFromModFile(final IModFile modFile, final Path path) {
+        try {
+            return Optional.of(Files.newInputStream(modFile.findResource(path.toString())));
+        }
+        catch (final FileNotFoundException e) {
+            LOGGER.debug("Failed to load resource {} from {}, it does not contain dependency information.", path, modFile.getFileName());
+            return Optional.empty();
+        }
+        catch (final Exception e) {
+            LOGGER.error("Failed to load resource {} from mod {}, cause {}", path, modFile.getFileName(), e);
+            return Optional.empty();
+        }
+    }
+
+    protected Optional<IModFile> loadModFileFrom(final IModFile file, final Path path) {
+        try {
+            final Path pathInModFile = file.findResource(path.toString());
+            return createMod(pathInModFile);
+        }
+        catch (Exception e) {
+            LOGGER.error("Failed to load mod file {} from {}", path, file.getFileName());
+            return Optional.empty();
+        }
+    }
+
+    protected String identifyMod(final IModFile modFile) {
+        return modFile.getFileName();
+    }
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/AbstractJarFileLocator.java

@@ -5,23 +5,22 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.SecureJar;
+import net.minecraftforge.fml.loading.LogMarkers;
+import net.minecraftforge.forgespi.locating.IModFile;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.List;
-import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Function;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import net.minecraftforge.fml.loading.LogMarkers;
-import net.minecraftforge.forgespi.locating.IModFile;
-import org.slf4j.Logger;
 
-public abstract class AbstractJarFileLocator extends AbstractModLocator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+public abstract class AbstractJarFileLocator extends AbstractModLocator
+{
+    private static final Logger LOGGER = LogManager.getLogger();
 
     @Override
     public void scanFile(final IModFile file, final Consumer<Path> pathConsumer) {
@@ -34,15 +33,4 @@ public abstract class AbstractJarFileLocator extends AbstractModLocator {
         }
         LOGGER.debug(LogMarkers.SCAN,"Scan finished: {}", file);
     }
-
-    @Override
-    public List<IModFile> scanMods() {
-        return scanCandidates()
-                .map(this::createMod)
-                .filter(Optional::isPresent)
-                .map(Optional::get)
-                .collect(Collectors.toList());
-    }
-
-    public abstract Stream<Path> scanCandidates();
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/AbstractJarFileModLocator.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading.moddiscovery;
+
+import net.minecraftforge.forgespi.locating.IModFile;
+import net.minecraftforge.forgespi.locating.IModLocator;
+
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public abstract class AbstractJarFileModLocator extends AbstractJarFileLocator implements IModLocator
+{
+    @Override
+    public List<IModFile> scanMods()
+    {
+        return scanCandidates()
+                .map(this::createMod)
+                .filter(Optional::isPresent)
+                .map(Optional::get)
+                .collect(Collectors.toList());
+    }
+
+    public abstract Stream<Path> scanCandidates();
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/AbstractModLocator.java

@@ -5,7 +5,6 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.JarMetadata;
 import cpw.mods.jarhandling.SecureJar;
 import net.minecraftforge.fml.loading.LogMarkers;
@@ -14,7 +13,8 @@ import net.minecraftforge.forgespi.language.IModFileInfo;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.locating.IModFile;
 import net.minecraftforge.forgespi.locating.IModLocator;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
 import java.util.Collections;
@@ -24,12 +24,18 @@ import java.util.Optional;
 import java.util.function.Function;
 import java.util.jar.Manifest;
 
-public abstract class AbstractModLocator implements IModLocator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+public abstract class AbstractModLocator implements IModLocator
+{
+    private static final   Logger LOGGER    = LogManager.getLogger();
     protected static final String MODS_TOML = "META-INF/mods.toml";
     protected static final String MANIFEST = "META-INF/MANIFEST.MF";
 
     protected Optional<IModFile> createMod(Path... path) {
+        return this.createMod(getDefaultJarModType(), path);
+    }
+
+    // FORGE: Backporting artifact, the defaultType must be the first parameter since path is varargs
+    protected Optional<IModFile> createMod(String defaultType, Path... path) {
         var mjm = new ModJarMetadata();
         var sj = SecureJar.from(
                 Manifest::new,
@@ -40,12 +46,15 @@ public abstract class AbstractModLocator implements IModLocator {
 
         IModFile mod;
         var type = sj.getManifest().getMainAttributes().getValue(ModFile.TYPE);
+        if (type == null) {
+            type = defaultType;
+        }
         if (sj.findFile(MODS_TOML).isPresent()) {
             LOGGER.debug(LogMarkers.SCAN, "Found {} mod of type {}: {}", MODS_TOML, type, path);
             mod = new ModFile(sj, this, ModFileParser::modsTomlParser);
         } else if (type != null) {
             LOGGER.debug(LogMarkers.SCAN, "Found {} mod of type {}: {}", MANIFEST, type, path);
-            mod = new ModFile(sj, this, this::manifestParser);
+            mod = new ModFile(sj, this, this::manifestParser, type);
         } else {
             return Optional.empty();
         }
@@ -68,29 +77,49 @@ public abstract class AbstractModLocator implements IModLocator {
             }
         };
 
-        return new IModFileInfo() {
-            @Override public List<IModInfo> getMods() { return Collections.emptyList(); }
-            @Override public List<LanguageSpec> requiredLanguageLoaders() { return Collections.emptyList(); }
-            @Override public boolean showAsResourcePack() { return false; }
-            @Override public Map<String, Object> getFileProperties() { return Collections.emptyMap(); }
-            @Override public String getLicense() { return license; }
-            @Override public IModFile getFile() { return mod; }
-            @Override public IConfigurable getConfig() { return dummy; }
-
-            // These Should never be called as it's only called from ModJarMetadata.version and we bypass that
-            @Override public String moduleName() { return mod.getSecureJar().name(); }
-            @Override public String versionString() { return null; }
-            @Override public List<String> usesServices() { return null; }
-
-            @Override
-            public String toString() {
-                return "IModFileInfo(" + mod.getFilePath() + ")";
-            }
-        };
+        return new DefaultModFileInfo(mod, license, dummy);
     }
 
     @Override
     public boolean isValid(final IModFile modFile) {
         return true;
     }
+
+    protected String getDefaultJarModType() {
+        return null;
+    }
+
+    private record DefaultModFileInfo(IModFile mod, String license, IConfigurable configurable) implements IModFileInfo, IConfigurable {
+        @Override
+        public <T> Optional<T> getConfigElement(final String... strings)
+        {
+            return Optional.empty();
+        }
+
+        @Override
+        public List<? extends IConfigurable> getConfigList(final String... strings)
+        {
+            return null;
+        }
+
+        @Override public List<IModInfo> getMods() { return Collections.emptyList(); }
+        @Override public List<LanguageSpec> requiredLanguageLoaders() { return Collections.emptyList(); }
+        @Override public boolean showAsResourcePack() { return false; }
+        @Override public Map<String, Object> getFileProperties() { return Collections.emptyMap(); }
+        @Override
+        public String getLicense() { return license; }
+
+        @Override public IModFile getFile() { return mod; }
+        @Override public IConfigurable getConfig() { return configurable; }
+
+        // These Should never be called as it's only called from ModJarMetadata.version and we bypass that
+        @Override public String moduleName() { return mod.getSecureJar().name(); }
+        @Override public String versionString() { return null; }
+        @Override public List<String> usesServices() { return null; }
+
+        @Override
+        public String toString() {
+            return "IModFileInfo(" + mod.getFilePath() + ")";
+        }
+    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/BackgroundScanHandler.java

@@ -5,11 +5,11 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.LoadingModList;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.forgespi.language.ModFileScanData;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.time.Duration;
 import java.time.Instant;
@@ -28,7 +28,7 @@ public class BackgroundScanHandler
         ERRORED
     }
 
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final ExecutorService modContentScanner;
     private final List<ModFile> pendingFiles;
     private final List<ModFile> scannedFiles;

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ClasspathLocator.java

@@ -5,18 +5,16 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
+import net.minecraftforge.fml.loading.ClasspathLocatorUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.File;
 import java.io.IOException;
-import java.net.URI;
-import java.net.URISyntaxException;
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Enumeration;
@@ -24,8 +22,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
 
-public class ClasspathLocator extends AbstractJarFileLocator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+public class ClasspathLocator extends AbstractJarFileModLocator {
+    private static final Logger LOGGER = LogManager.getLogger();
     private final List<Path> legacyClasspath = Arrays.stream(System.getProperty("legacyClassPath", "").split(File.pathSeparator)).map(Path::of).toList();
     private boolean enabled = false;
 
@@ -48,7 +46,7 @@ public class ClasspathLocator extends AbstractJarFileLocator {
 
             return paths.build();
         } catch (IOException e) {
-            LOGGER.error(LogMarkers.SCAN, "Error trying to find resources", e);
+            LOGGER.fatal(LogMarkers.SCAN, "Error trying to find resources", e);
             throw new RuntimeException(e);
         }
     }
@@ -58,7 +56,7 @@ public class ClasspathLocator extends AbstractJarFileLocator {
         final Enumeration<URL> resources = ClassLoader.getSystemClassLoader().getResources(resource);
         while (resources.hasMoreElements()) {
             URL url = resources.nextElement();
-            Path path = findJarPathFor(resource, resource, url);
+            Path path = ClasspathLocatorUtils.findJarPathFor(resource, resource, url);
             if (claimed.stream().anyMatch(path::equals) || !Files.exists(path) || Files.isDirectory(path))
                 continue;
             ret.add(path);
@@ -71,22 +69,4 @@ public class ClasspathLocator extends AbstractJarFileLocator {
         var launchTarget = (String) arguments.get("launchTarget");
         enabled = launchTarget != null && launchTarget.contains("dev");
     }
-
-    private Path findJarPathFor(final String resourceName, final String jarName, final URL resource) {
-        try {
-            Path path;
-            final URI uri = resource.toURI();
-            if (uri.getScheme().equals("jar") && uri.getRawSchemeSpecificPart().contains("!/")) {
-                int lastExcl = uri.getRawSchemeSpecificPart().lastIndexOf("!/");
-                path = Paths.get(new URI(uri.getRawSchemeSpecificPart().substring(0, lastExcl)));
-            } else {
-                path = Paths.get(new URI("file://"+uri.getRawSchemeSpecificPart().substring(0, uri.getRawSchemeSpecificPart().length()-resourceName.length())));
-            }
-            //LOGGER.debug(CORE, "Found JAR {} at path {}", jarName, path.toString());
-            return path;
-        } catch (NullPointerException | URISyntaxException e) {
-            LOGGER.error(LogMarkers.SCAN, "Failed to find JAR for class {} - {}", resourceName, jarName);
-            throw new RuntimeException("Unable to locate "+resourceName+" - "+jarName, e);
-        }
-    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ExplodedDirectoryLocator.java

@@ -5,11 +5,11 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.forgespi.locating.IModFile;
 import net.minecraftforge.forgespi.locating.IModLocator;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -22,7 +22,7 @@ import java.util.function.Consumer;
 import java.util.stream.Stream;
 
 public class ExplodedDirectoryLocator implements IModLocator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
 
     public record ExplodedMod(String modid, List<Path> paths) {}
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/JarInJarDependencyLocator.java

@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.fml.loading.moddiscovery;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import net.minecraftforge.fml.loading.EarlyLoadingException;
+import net.minecraftforge.forgespi.language.IModInfo;
+import net.minecraftforge.forgespi.locating.IModFile;
+import net.minecraftforge.jarjar.selection.JarSelector;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+import org.apache.maven.artifact.versioning.VersionRange;
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class JarInJarDependencyLocator extends AbstractJarFileDependencyLocator
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    @Override
+    public String name()
+    {
+        return "JarInJar";
+    }
+
+    @Override
+    public List<IModFile> scanMods(final Iterable<IModFile> loadedMods)
+    {
+        final List<IModFile> sources = Lists.newArrayList();
+        loadedMods.forEach(sources::add);
+
+
+        final List<IModFile> dependenciesToLoad = JarSelector.detectAndSelect(sources, this::loadResourceFromModFile, this::loadModFileFrom, this::identifyMod, this::exception);
+
+        if (dependenciesToLoad.isEmpty())
+        {
+            LOGGER.info("No dependencies to load found. Skipping!");
+            return Collections.emptyList();
+        }
+
+        LOGGER.info("Found {} dependencies adding them to mods collection", dependenciesToLoad.size());
+        return dependenciesToLoad;
+    }
+
+    @Override
+    public void initArguments(final Map<String, ?> arguments)
+    {
+        // NO-OP, for now
+    }
+
+    @Override
+    protected String getDefaultJarModType()
+    {
+        return IModFile.Type.GAMELIBRARY.name();
+    }
+
+    @SuppressWarnings("resource")
+    @Override
+    protected Optional<IModFile> loadModFileFrom(final IModFile file, final Path path)
+    {
+        try
+        {
+            final Path pathInModFile = file.findResource(path.toString());
+            final URI filePathUri = new URI("jij:" + (pathInModFile.toAbsolutePath().toUri().getRawSchemeSpecificPart())).normalize();
+            final Map<String, ?> outerFsArgs = ImmutableMap.of("packagePath", pathInModFile);
+            final FileSystem zipFS = FileSystems.newFileSystem(filePathUri, outerFsArgs);
+            final Path pathInFS = zipFS.getPath("/");
+            final IModFile.Type parentType = file.getType();
+            final String modType;
+            if (parentType == IModFile.Type.LIBRARY || parentType == IModFile.Type.LANGPROVIDER) {
+                modType = IModFile.Type.LIBRARY.name();
+            } else {
+                modType = IModFile.Type.GAMELIBRARY.name();
+            }
+            return createMod(modType, pathInFS);
+        }
+        catch (Exception e)
+        {
+            LOGGER.error("Failed to load mod file {} from {}", path, file.getFileName());
+
+            throw new RuntimeException("Failed to load mod file " + file.getFileName(), e);
+        }
+    }
+
+    protected EarlyLoadingException exception(Collection<JarSelector.ResolutionFailureInformation<IModFile>> failedDependencies)
+    {
+
+        final List<EarlyLoadingException.ExceptionData> errors = failedDependencies.stream()
+               .filter(entry -> !entry.sources().isEmpty()) //Should never be the case, but just to be sure
+               .map(this::buildExceptionData)
+               .toList();
+
+        return new EarlyLoadingException(failedDependencies.size() + " Dependency restrictions were not met.", null, errors);
+    }
+
+    @NotNull
+    private EarlyLoadingException.ExceptionData buildExceptionData(final JarSelector.ResolutionFailureInformation<IModFile> entry)
+    {
+        return new EarlyLoadingException.ExceptionData(
+                getErrorTranslationKey(entry),
+                entry.identifier().group() + ":" + entry.identifier().artifact(),
+                entry.sources()
+                     .stream()
+                     .flatMap(this::getModWithVersionRangeStream)
+                     .map(this::formatError)
+                     .collect(Collectors.joining(", "))
+        );
+    }
+
+    @NotNull
+    private String getErrorTranslationKey(final JarSelector.ResolutionFailureInformation<IModFile> entry)
+    {
+        return entry.failureReason() == JarSelector.FailureReason.VERSION_RESOLUTION_FAILED ?
+                       "fml.dependencyloading.conflictingdependencies" :
+                       "fml.dependencyloading.mismatchedcontaineddependencies";
+    }
+
+    @NotNull
+    private Stream<ModWithVersionRange> getModWithVersionRangeStream(final JarSelector.SourceWithRequestedVersionRange<IModFile> file)
+    {
+        return file.sources()
+                   .stream()
+                   .map(IModFile::getModFileInfo)
+                   .flatMap(modFileInfo -> modFileInfo.getMods().stream())
+                   .map(modInfo -> new ModWithVersionRange(modInfo, file.requestedVersionRange(), file.includedVersion()));
+    }
+
+    @NotNull
+    private String formatError(final ModWithVersionRange modWithVersionRange)
+    {
+        return "\u00a7e" + modWithVersionRange.modInfo().getModId() + "\u00a7r - \u00a74" + modWithVersionRange.versionRange().toString() + "\u00a74 - \u00a72" + modWithVersionRange.artifactVersion().toString() + "\u00a72";
+    }
+
+    @Override
+    protected String identifyMod(final IModFile modFile)
+    {
+        if (modFile.getModFileInfo() == null || modFile.getModInfos().isEmpty())
+        {
+            return modFile.getFileName();
+        }
+
+        return modFile.getModInfos().stream().map(IModInfo::getModId).collect(Collectors.joining());
+    }
+
+    private record ModWithVersionRange(IModInfo modInfo, VersionRange versionRange, ArtifactVersion artifactVersion)
+    {}
+}

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/MavenDirectoryLocator.java

@@ -15,7 +15,7 @@ import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class MavenDirectoryLocator extends AbstractJarFileLocator {
+public class MavenDirectoryLocator extends AbstractJarFileModLocator {
     private List<Path> modCoords;
 
     @Override

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/MinecraftLocator.java

@@ -6,14 +6,15 @@
 package net.minecraftforge.fml.loading.moddiscovery;
 
 import com.electronwill.nightconfig.core.Config;
-import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.SecureJar;
 import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.forgespi.language.IModFileInfo;
 import net.minecraftforge.forgespi.locating.IModFile;
+import net.minecraftforge.forgespi.locating.IModLocator;
 import net.minecraftforge.forgespi.locating.ModFileFactory;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.nio.file.*;
@@ -22,8 +23,8 @@ import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class MinecraftLocator extends AbstractModLocator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+public class MinecraftLocator extends AbstractModLocator implements IModLocator {
+    private static final Logger LOGGER = LogManager.getLogger();
 
     @Override
     public List<IModFile> scanMods() {

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModDiscoverer.java

@@ -5,16 +5,20 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Maps;
 import cpw.mods.modlauncher.Launcher;
 import cpw.mods.modlauncher.api.IModuleLayerManager;
 import cpw.mods.modlauncher.util.ServiceLoaderUtils;
+import net.minecraftforge.fml.loading.EarlyLoadingException;
 import net.minecraftforge.fml.loading.LogMarkers;
+import net.minecraftforge.fml.loading.UniqueModListBuilder;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.Environment;
 import net.minecraftforge.forgespi.locating.IModFile;
 import net.minecraftforge.forgespi.locating.IModLocator;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -23,48 +27,120 @@ import java.util.ServiceLoader;
 import java.util.stream.Collectors;
 
 public class ModDiscoverer {
-    private static final Logger LOGGER = LogUtils.getLogger();
-    private final ServiceLoader<IModLocator> locators;
-    private final List<IModLocator> locatorList;
+    private static final Logger LOGGER = LogManager.getLogger();
+    private final ServiceLoader<IModLocator> modLocators;
+    private final List<IModLocator>          modLocatorList;
 
     public ModDiscoverer(Map<String, ?> arguments) {
         Launcher.INSTANCE.environment().computePropertyIfAbsent(Environment.Keys.MODDIRECTORYFACTORY.get(), v->ModsFolderLocator::new);
         Launcher.INSTANCE.environment().computePropertyIfAbsent(Environment.Keys.PROGRESSMESSAGE.get(), v-> StartupMessageManager.locatorConsumer().orElseGet(()-> s->{}));
         final var moduleLayerManager = Launcher.INSTANCE.environment().findModuleLayerManager().orElseThrow();
-        locators = ServiceLoader.load(moduleLayerManager.getLayer(IModuleLayerManager.Layer.SERVICE).orElseThrow(), IModLocator.class);
-        locatorList = ServiceLoaderUtils.streamServiceLoader(()->locators, sce->LOGGER.error("Failed to load locator list", sce)).collect(Collectors.toList());
-        locatorList.forEach(l->l.initArguments(arguments));
+        modLocators = ServiceLoader.load(moduleLayerManager.getLayer(IModuleLayerManager.Layer.SERVICE).orElseThrow(), IModLocator.class);
+        modLocatorList = ServiceLoaderUtils.streamServiceLoader(()-> modLocators, sce->LOGGER.error("Failed to load mod locator list", sce)).collect(Collectors.toList());
+        modLocatorList.forEach(l->l.initArguments(arguments));
         if (LOGGER.isDebugEnabled(LogMarkers.CORE))
         {
-            LOGGER.debug(LogMarkers.CORE, "Found Mod Locators : {}", locatorList.stream()
-                    .map(iModLocator -> "(" + iModLocator.name() + ":" + iModLocator.getClass().getPackage().getImplementationVersion() + ")").collect(Collectors.joining(",")));
+            LOGGER.debug(LogMarkers.CORE, "Found Mod Locators : {}", modLocatorList.stream()
+                                                                       .map(modLocator -> "(%s:%s)".formatted(modLocator.name(),
+                                                                         modLocator.getClass().getPackage().getImplementationVersion())).collect(Collectors.joining(",")));
         }
     }
 
-    ModDiscoverer(List<IModLocator> locatorList) {
-        this.locatorList = locatorList;
-        this.locators = null;
-    }
-
     public ModValidator discoverMods() {
-        LOGGER.debug(LogMarkers.SCAN,"Scanning for mods and other resources to load. We know {} ways to find mods", locatorList.size());
-        var loadedFiles = new ArrayList<>();
-        for (IModLocator locator : locatorList) {
-            LOGGER.debug(LogMarkers.SCAN,"Trying locator {}", locator);
-            var modFiles = locator.scanMods();
-            for (IModFile mf : modFiles) {
-                LOGGER.info(LogMarkers.SCAN, "Found mod file {} of type {} with locator {}", mf.getFileName(), mf.getType(), mf.getLocator());
-                StartupMessageManager.modLoaderConsumer().ifPresent(c->c.accept("Found mod file "+mf.getFileName()+" of type "+mf.getType()));
-            }
-            loadedFiles.addAll(modFiles);
-        }
-        final var modFilesMap = loadedFiles.stream()
-                .map(ModFile.class::cast)
-                .collect(Collectors.groupingBy(IModFile::getType));
+        LOGGER.debug(LogMarkers.SCAN,"Scanning for mods and other resources to load. We know {} ways to find mods", modLocatorList.size());
+        List<ModFile> loadedFiles = new ArrayList<>();
+        List<EarlyLoadingException.ExceptionData> discoveryErrorData = new ArrayList<>();
+        boolean successfullyLoadedMods = true;
 
-        var validator = new ModValidator(modFilesMap);
+        //Loop all mod locators to get the prime mods to load from.
+        for (IModLocator locator : modLocatorList) {
+            try {
+                LOGGER.debug(LogMarkers.SCAN,"Trying locator {}", locator);
+                var locatedFiles = locator.scanMods();
+
+                if (locatedFiles.stream().anyMatch(file -> !(file instanceof ModFile))) {
+                    LOGGER.error(LogMarkers.SCAN, "A mod locator returned a file which is not a ModFile instance!. They will be skipped!");
+                }
+
+                handleLocatedFiles(loadedFiles, locatedFiles);
+            } catch (EarlyLoadingException exception) {
+                LOGGER.error(LogMarkers.SCAN, "Failed to load mods with locator {}", locator, exception);
+                discoveryErrorData.addAll(exception.getAllData());
+            }
+        }
+
+        //First processing run of the mod list. Any duplicates will cause resolution failure and dependency loading will be skipped.
+        Map<IModFile.Type, List<ModFile>> modFilesMap = Maps.newHashMap();
+        try {
+            final UniqueModListBuilder modsUniqueListBuilder = new UniqueModListBuilder(loadedFiles);
+            final UniqueModListBuilder.UniqueModListData uniqueModsData = modsUniqueListBuilder.buildUniqueList();
+
+            //Grab the temporary results.
+            //This allows loading to continue to a base state, in case dependency loading fails.
+            modFilesMap = uniqueModsData.modFiles().stream()
+                            .collect(Collectors.groupingBy(IModFile::getType));
+            loadedFiles = uniqueModsData.modFiles();
+        }
+        catch (EarlyLoadingException exception) {
+            LOGGER.error(LogMarkers.SCAN, "Failed to build unique mod list after mod discovery.", exception);
+            discoveryErrorData.addAll(exception.getAllData());
+            successfullyLoadedMods = false;
+        }
+
+        //We can continue loading if prime mods loaded successfully.
+        if (successfullyLoadedMods) {
+            LOGGER.debug(LogMarkers.SCAN, "Successfully Loaded {} mods. Attempting to load dependencies...", loadedFiles.size());
+            for (IModLocator locator : modLocatorList) {
+                try {
+                    LOGGER.debug(LogMarkers.SCAN,"Trying locator {}", locator);
+                    final List<IModFile> locatedMods = ImmutableList.copyOf(loadedFiles);
+
+                    var locatedFiles = locator.scanMods(locatedMods);
+                    if (locatedFiles.stream().anyMatch(file -> !(file instanceof ModFile))) {
+                        LOGGER.error(LogMarkers.SCAN, "A dependency locator returned a file which is not a ModFile instance!. They will be skipped!");
+                    }
+
+                    handleLocatedFiles(loadedFiles, locatedFiles);
+                }
+                catch (EarlyLoadingException exception) {
+                    LOGGER.error(LogMarkers.SCAN, "Failed to load dependencies with locator {}", locator, exception);
+                    discoveryErrorData.addAll(exception.getAllData());
+                }
+            }
+
+            //Second processing run of the mod list. Any duplicates will cause resolution failure and only the mods list will be loaded.
+            try {
+                final UniqueModListBuilder modsAndDependenciesUniqueListBuilder = new UniqueModListBuilder(loadedFiles);
+                final UniqueModListBuilder.UniqueModListData uniqueModsAndDependenciesData = modsAndDependenciesUniqueListBuilder.buildUniqueList();
+
+                //We now only need the mod files map, not the list.
+                modFilesMap = uniqueModsAndDependenciesData.modFiles().stream()
+                                .collect(Collectors.groupingBy(IModFile::getType));
+            } catch (EarlyLoadingException exception) {
+                LOGGER.error(LogMarkers.SCAN, "Failed to build unique mod list after dependency discovery.", exception);
+                discoveryErrorData.addAll(exception.getAllData());
+                modFilesMap = loadedFiles.stream().collect(Collectors.groupingBy(IModFile::getType));
+            }
+        }
+        else {
+            //Failure notify the listeners.
+            LOGGER.error(LogMarkers.SCAN, "Mod Discovery failed. Skipping dependency discovery.");
+        }
+
+        //Validate the loading. With a deduplicated list, we can now successfully process the artifacts and load
+        //transformer plugins.
+        var validator = new ModValidator(modFilesMap, discoveryErrorData);
         validator.stage1Validation();
         return validator;
     }
 
+    private void handleLocatedFiles(final List<ModFile> loadedFiles, final List<IModFile> locatedFiles)
+    {
+        var locatedModFiles = locatedFiles.stream().filter(ModFile.class::isInstance).map(ModFile.class::cast).toList();
+        for (IModFile mf : locatedModFiles) {
+            LOGGER.info(LogMarkers.SCAN, "Found mod file {} of type {} with provider {}", mf.getFileName(), mf.getType(), mf.getLocator());
+            StartupMessageManager.modLoaderConsumer().ifPresent(c->c.accept("Found mod file "+mf.getFileName()+" of type "+mf.getType()));
+        }
+        loadedFiles.addAll(locatedModFiles);
+    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModFile.java

@@ -6,7 +6,6 @@
 package net.minecraftforge.fml.loading.moddiscovery;
 
 import com.google.common.collect.ImmutableMap;
-import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.SecureJar;
 import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.LogMarkers;
@@ -18,7 +17,10 @@ import net.minecraftforge.forgespi.language.ModFileScanData;
 import net.minecraftforge.forgespi.locating.IModFile;
 import net.minecraftforge.forgespi.locating.IModLocator;
 import net.minecraftforge.forgespi.locating.ModFileFactory;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -37,7 +39,7 @@ public class ModFile implements IModFile {
     // Mods either must have a mods.toml or a manifest. We can no longer just put any jar on the classpath.
     @Deprecated(forRemoval = true, since = "1.18")
     public static final Manifest DEFAULTMANIFEST;
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
 
     static {
         DEFAULTMANIFEST = new Manifest();
@@ -51,9 +53,9 @@ public class ModFile implements IModFile {
     private Throwable scanError;
     private final SecureJar jar;
     private final Type modFileType;
-    private final Manifest manifest;
+    private final Manifest     manifest;
     private final IModLocator locator;
-    private IModFileInfo modFileInfo;
+    private       IModFileInfo modFileInfo;
     private ModFileScanData fileModFileScanData;
     private CompletableFuture<ModFileScanData> futureScanResult;
     private List<CoreModFile> coreMods;
@@ -63,14 +65,18 @@ public class ModFile implements IModFile {
     private SecureJar.Status securityStatus;
 
     public ModFile(final SecureJar jar, final IModLocator locator, final ModFileFactory.ModFileInfoParser parser) {
+        this(jar, locator, parser, parseType(jar));
+    }
+
+    public ModFile(final SecureJar jar, final IModLocator locator, final ModFileFactory.ModFileInfoParser parser, String type) {
         this.locator = locator;
         this.jar = jar;
         this.parser = parser;
 
         manifest = this.jar.getManifest();
-        final Optional<String> value = Optional.ofNullable(manifest.getMainAttributes().getValue(TYPE));
-        modFileType = Type.valueOf(value.orElse("MOD"));
+        modFileType = Type.valueOf(type);
         jarVersion = Optional.ofNullable(manifest.getMainAttributes().getValue(Attributes.Name.IMPLEMENTATION_VERSION)).orElse("0.0NONE");
+        this.modFileInfo = ModFileParser.readModList(this, this.parser);
     }
 
     @Override
@@ -201,4 +207,15 @@ public class ModFile implements IModFile {
     public void setSecurityStatus(final SecureJar.Status status) {
         this.securityStatus = status;
     }
+
+    public ArtifactVersion getJarVersion()
+    {
+        return new DefaultArtifactVersion(this.jarVersion);
+    }
+
+    private static String parseType(final SecureJar jar) {
+        final Manifest m = jar.getManifest();
+        final Optional<String> value = Optional.ofNullable(m.getMainAttributes().getValue(TYPE));
+        return value.orElse("MOD");
+    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModFileInfo.java

@@ -6,7 +6,6 @@
 package net.minecraftforge.fml.loading.moddiscovery;
 
 import com.google.common.base.Strings;
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.fml.loading.StringUtils;
@@ -14,7 +13,8 @@ import net.minecraftforge.forgespi.language.IConfigurable;
 import net.minecraftforge.forgespi.language.IModFileInfo;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.MavenVersionAdapter;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import javax.security.auth.x500.X500Principal;
 import java.net.URL;
 import java.security.CodeSigner;
@@ -32,7 +32,7 @@ import java.util.stream.Stream;
 
 public class ModFileInfo implements IModFileInfo, IConfigurable
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final IConfigurable config;
     private final ModFile modFile;
     private final URL issueURL;
@@ -68,13 +68,10 @@ public class ModFileInfo implements IModFileInfo, IConfigurable
         this.mods = modConfigs.stream()
                 .map(mi-> new ModInfo(this, mi))
                 .collect(Collectors.toList());
-        if (LOGGER.isDebugEnabled(LogMarkers.LOADING))
-        {
-            LOGGER.debug(LogMarkers.LOADING, "Found valid mod file {} with {} mods - versions {}",
-                    this.modFile.getFileName(),
-                    this.mods.stream().map(IModInfo::getModId).collect(Collectors.joining(",", "{", "}")),
-                    this.mods.stream().map(IModInfo::getVersion).map(Objects::toString).collect(Collectors.joining(",", "{", "}")));
-        }
+        LOGGER.debug(LogMarkers.LOADING, "Found valid mod file {} with {} mods - versions {}",
+                this.modFile::getFileName,
+                () -> this.mods.stream().map(IModInfo::getModId).collect(Collectors.joining(",", "{", "}")),
+                () -> this.mods.stream().map(IModInfo::getVersion).map(Objects::toString).collect(Collectors.joining(",", "{", "}")));
     }
 
     public ModFileInfo(final ModFile file, final IConfigurable config, final List<LanguageSpec> languageSpecs) {

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModFileParser.java

@@ -8,12 +8,12 @@ package net.minecraftforge.fml.loading.moddiscovery;
 import com.electronwill.nightconfig.core.file.FileConfig;
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.forgespi.language.IModFileInfo;
 import net.minecraftforge.forgespi.locating.IModFile;
 import net.minecraftforge.forgespi.locating.ModFileFactory;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.lang.reflect.Type;
@@ -25,7 +25,7 @@ import java.util.Map;
 import java.util.stream.Collectors;
 
 public class ModFileParser {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
 
     public static IModFileInfo readModList(final ModFile modFile, final ModFileFactory.ModFileInfoParser parser) {
         return parser.build(modFile);

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModInfo.java

@@ -5,18 +5,16 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.StringSubstitutor;
 import net.minecraftforge.fml.loading.StringUtils;
 import net.minecraftforge.forgespi.language.IConfigurable;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.MavenVersionAdapter;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 import org.apache.maven.artifact.versioning.VersionRange;
-import org.slf4j.Logger;
-import org.slf4j.Marker;
-import org.slf4j.MarkerFactory;
 
 import java.net.URL;
 import java.util.Collections;
@@ -28,7 +26,7 @@ import java.util.stream.Collectors;
 
 public class ModInfo implements IModInfo, IConfigurable
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private static final DefaultArtifactVersion DEFAULT_VERSION = new DefaultArtifactVersion("1");
     private static final Pattern VALID_MODID = Pattern.compile("^[a-z][a-z0-9_]{1,63}$");
     private static final Pattern VALID_NAMESPACE = Pattern.compile("^[a-z][a-z0-9_.-]{1,63}$");
@@ -54,19 +52,21 @@ public class ModInfo implements IModInfo, IConfigurable
         this.modId = config.<String>getConfigElement("modId")
                 .orElseThrow(() -> new InvalidModFileException("Missing modId", owningFile));
         if (!VALID_MODID.matcher(this.modId).matches()) {
-            LOGGER.error(LogUtils.FATAL_MARKER, "Invalid modId found in file {} - {} does not match the standard: {}", this.owningFile.getFile().getFilePath(), this.modId, VALID_MODID.pattern());
+            LOGGER.fatal("Invalid modId found in file {} - {} does not match the standard: {}", this.owningFile.getFile().getFilePath(), this.modId, VALID_MODID.pattern());
             throw new InvalidModFileException("Invalid modId found : " + this.modId, owningFile);
         }
         this.namespace = config.<String>getConfigElement("namespace").orElse(this.modId);
         if (!VALID_NAMESPACE.matcher(this.namespace).matches()) {
-            LOGGER.error(LogUtils.FATAL_MARKER, "Invalid override namespace found in file {} - {} does not match the standard: {}", this.owningFile.getFile().getFilePath(), this.namespace, VALID_NAMESPACE.pattern());
+            LOGGER.fatal("Invalid override namespace found in file {} - {} does not match the standard: {}", this.owningFile.getFile().getFilePath(), this.namespace, VALID_NAMESPACE.pattern());
             throw new InvalidModFileException("Invalid override namespace found : " + this.namespace, owningFile);
         }
         this.version = config.<String>getConfigElement("version")
                 .map(s -> StringSubstitutor.replace(s, ownFile.map(ModFileInfo::getFile).orElse(null)))
                 .map(DefaultArtifactVersion::new).orElse(DEFAULT_VERSION);
         this.displayName = config.<String>getConfigElement("displayName").orElse(this.modId);
-        this.description = config.<String>getConfigElement("description").orElse("MISSING DESCRIPTION");
+        this.description = config.<String>getConfigElement("description")
+                .orElse("MISSING DESCRIPTION")
+                .replace("\r\n", "\n").stripIndent();
 
         this.logoFile = Optional.ofNullable(config.<String>getConfigElement("logoFile")
                 .orElseGet(() -> ownFile.flatMap(mf -> mf.<String>getConfigElement("logoFile")).orElse(null)));

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModListHandler.java

@@ -5,13 +5,13 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.FMLPaths;
 import net.minecraftforge.fml.loading.FileUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.fml.loading.MavenCoordinateResolver;
 import org.apache.commons.lang3.tuple.Pair;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -23,7 +23,7 @@ import java.util.Objects;
 import java.util.stream.Collectors;
 
 public class ModListHandler {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     /**
      * Reads the modList paths specified, and searches each maven root for mods matching. Returns a list of mods
      * found.

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModValidator.java

@@ -5,7 +5,6 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.IModuleLayerManager;
 import cpw.mods.modlauncher.api.ITransformationService;
 import net.minecraftforge.fml.loading.EarlyLoadingException;
@@ -14,25 +13,28 @@ import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.fml.loading.ModSorter;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.locating.IModFile;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
-import org.slf4j.Logger;
 
 import java.util.*;
 
 public class ModValidator {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final Map<IModFile.Type, List<ModFile>> modFiles;
     private final List<ModFile> candidatePlugins;
     private final List<ModFile> candidateMods;
     private LoadingModList loadingModList;
     private List<ModFile> brokenFiles;
+    private final List<EarlyLoadingException.ExceptionData> discoveryErrorData;
 
-    public ModValidator(final Map<IModFile.Type, List<ModFile>> modFiles) {
+    public ModValidator(final Map<IModFile.Type, List<ModFile>> modFiles, final List<EarlyLoadingException.ExceptionData> discoveryErrorData) {
         this.modFiles = modFiles;
         this.candidateMods = lst(modFiles.get(IModFile.Type.MOD));
         this.candidateMods.addAll(lst(modFiles.get(IModFile.Type.GAMELIBRARY)));
         this.candidatePlugins = lst(modFiles.get(IModFile.Type.LANGPROVIDER));
         this.candidatePlugins.addAll(lst(modFiles.get(IModFile.Type.LIBRARY)));
+        this.discoveryErrorData = discoveryErrorData;
     }
 
     private static List<ModFile> lst(List<ModFile> files) {
@@ -41,9 +43,7 @@ public class ModValidator {
 
     public void stage1Validation() {
         brokenFiles = validateFiles(candidateMods);
-        if (LOGGER.isDebugEnabled(LogMarkers.SCAN)) {
-            LOGGER.debug(LogMarkers.SCAN, "Found {} mod files with {} mods", candidateMods.size(), candidateMods.stream().mapToInt(mf -> mf.getModInfos().size()).sum());
-        }
+        LOGGER.debug(LogMarkers.SCAN,"Found {} mod files with {} mods", candidateMods::size, ()-> candidateMods.stream().mapToInt(mf -> mf.getModInfos().size()).sum());
         StartupMessageManager.modLoaderConsumer().ifPresent(c->c.accept("Found "+ candidateMods.size()+" modfiles to load"));
     }
 
@@ -52,22 +52,22 @@ public class ModValidator {
         final List<ModFile> brokenFiles = new ArrayList<>();
         for (Iterator<ModFile> iterator = mods.iterator(); iterator.hasNext(); )
         {
-            ModFile mod = iterator.next();
-            if (!mod.getLocator().isValid(mod) || !mod.identifyMods()) {
-                LOGGER.warn(LogMarkers.SCAN, "File {} has been ignored - it is invalid", mod.getFilePath());
+            ModFile modFile = iterator.next();
+            if (!modFile.getLocator().isValid(modFile) || !modFile.identifyMods()) {
+                LOGGER.warn(LogMarkers.SCAN, "File {} has been ignored - it is invalid", modFile.getFilePath());
                 iterator.remove();
-                brokenFiles.add(mod);
+                brokenFiles.add(modFile);
             }
         }
         return brokenFiles;
     }
 
     public ITransformationService.Resource getPluginResources() {
-        return new ITransformationService.Resource(IModuleLayerManager.Layer.PLUGIN, this.candidatePlugins.stream().map(ModFile::getSecureJar).toList());
+        return new ITransformationService.Resource(IModuleLayerManager.Layer.PLUGIN, this.candidatePlugins.stream().map(IModFile::getSecureJar).toList());
     }
 
     public ITransformationService.Resource getModResources() {
-        return new ITransformationService.Resource(IModuleLayerManager.Layer.GAME, this.candidateMods.stream().map(ModFile::getSecureJar).toList());
+        return new ITransformationService.Resource(IModuleLayerManager.Layer.GAME, this.candidateMods.stream().map(IModFile::getSecureJar).toList());
     }
 
     private List<EarlyLoadingException.ExceptionData> validateLanguages() {
@@ -86,7 +86,11 @@ public class ModValidator {
 
     public BackgroundScanHandler stage2Validation() {
         var errors = validateLanguages();
-        loadingModList = ModSorter.sort(candidateMods, errors);
+
+        var allErrors = new ArrayList<>(errors);
+        allErrors.addAll(this.discoveryErrorData);
+
+        loadingModList = ModSorter.sort(candidateMods, allErrors);
         loadingModList.addCoreMods();
         loadingModList.addAccessTransformers();
         loadingModList.setBrokenFiles(brokenFiles);

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/ModsFolderLocator.java

@@ -5,12 +5,12 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.FMLPaths;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.fml.loading.ModDirTransformerDiscoverer;
 import net.minecraftforge.fml.loading.StringUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -23,9 +23,9 @@ import static cpw.mods.modlauncher.api.LamdbaExceptionUtils.uncheck;
 /**
  * Support loading mods located in JAR files in the mods folder
  */
-public class ModsFolderLocator extends AbstractJarFileLocator {
+public class ModsFolderLocator extends AbstractJarFileModLocator {
     private static final String SUFFIX = ".jar";
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final Path modFolder;
     private final String customName;
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/moddiscovery/Scanner.java

@@ -5,12 +5,12 @@
 
 package net.minecraftforge.fml.loading.moddiscovery;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
 import net.minecraftforge.forgespi.language.ModFileScanData;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.objectweb.asm.ClassReader;
-import org.slf4j.Logger;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -19,7 +19,7 @@ import java.nio.file.Path;
 import java.util.List;
 
 public class Scanner {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final ModFile fileToScan;
 
     public Scanner(final ModFile fileToScan) {

fmlloader/src/main/java/net/minecraftforge/fml/loading/progress/ClientVisualization.java

@@ -34,6 +34,8 @@ import java.util.function.IntSupplier;
 import java.util.function.LongSupplier;
 import java.util.function.Supplier;
 
+import javax.annotation.Nullable;
+
 import static org.lwjgl.glfw.GLFW.*;
 import static org.lwjgl.glfw.GLFW.glfwCreateWindow;
 import static org.lwjgl.opengl.GL11.*;

fmlloader/src/main/java/net/minecraftforge/fml/loading/targets/ArgumentList.java

@@ -5,8 +5,8 @@
 
 package net.minecraftforge.fml.loading.targets;
 
-import com.mojang.logging.LogUtils;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -20,7 +20,7 @@ import java.util.function.Supplier;
  * Can not use JOptSimple as that doesn't parse out the values for keys unless the spec says it has a value.
  */
 class ArgumentList {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private List<Supplier<String[]>> entries = new ArrayList<>();
     private Map<String, EntryValue> values = new HashMap<>();
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/targets/CommonClientLaunchHandler.java

@@ -10,12 +10,17 @@ import net.minecraftforge.fml.loading.LibraryFinder;
 import net.minecraftforge.fml.loading.VersionInfo;
 import net.minecraftforge.api.distmarker.Dist;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 import java.nio.file.Path;
 import java.util.List;
 import java.util.concurrent.Callable;
 import java.util.stream.Stream;
 
 public abstract class CommonClientLaunchHandler extends CommonLaunchHandler {
+    private static final Logger LOGGER = LogManager.getLogger();
+
     @Override public Dist getDist()  { return Dist.CLIENT; }
     @Override public String getNaming() { return "srg"; }
     @Override public boolean isProduction() { return true; }

fmlloader/src/main/java/net/minecraftforge/fml/loading/targets/CommonLaunchHandler.java

@@ -5,12 +5,12 @@
 
 package net.minecraftforge.fml.loading.targets;
 
-import com.mojang.logging.LogUtils;
 import cpw.mods.modlauncher.api.ILaunchHandlerService;
 import cpw.mods.modlauncher.api.ITransformingClassLoaderBuilder;
 import net.minecraftforge.fml.loading.LogMarkers;
 import net.minecraftforge.api.distmarker.Dist;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.io.File;
 import java.nio.file.Path;
@@ -25,7 +25,7 @@ import java.util.stream.Collectors;
 public abstract class CommonLaunchHandler implements ILaunchHandlerService {
     public record LocatedPaths(List<Path> minecraftPaths, BiPredicate<String, String> minecraftFilter, List<List<Path>> otherModPaths, List<Path> otherArtifacts) {}
 
-    protected static final Logger LOGGER = LogUtils.getLogger();
+    protected static final Logger LOGGER = LogManager.getLogger();
 
     public abstract Dist getDist();
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/targets/CommonServerLaunchHandler.java

@@ -10,6 +10,8 @@ import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.LibraryFinder;
 import net.minecraftforge.fml.loading.VersionInfo;
 import net.minecraftforge.api.distmarker.Dist;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
 import java.util.List;
@@ -18,6 +20,8 @@ import java.util.function.BiPredicate;
 import java.util.stream.Stream;
 
 public abstract class CommonServerLaunchHandler extends CommonLaunchHandler {
+    protected static final Logger LOGGER = LogManager.getLogger();
+
     @Override public Dist getDist()  { return Dist.DEDICATED_SERVER; }
     @Override public String getNaming() { return "srg"; }
     @Override public boolean isProduction() { return true; }

fmlloader/src/main/resources/META-INF/services/cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService

@@ -1 +1,2 @@
-net.minecraftforge.fml.loading.ModDirTransformerDiscoverer
+net.minecraftforge.fml.loading.ModDirTransformerDiscoverer
+net.minecraftforge.fml.loading.ClasspathTransformerDiscoverer

fmlloader/src/main/resources/META-INF/services/net.minecraftforge.forgespi.locating.IModLocator

@@ -3,3 +3,4 @@ net.minecraftforge.fml.loading.moddiscovery.MavenDirectoryLocator
 net.minecraftforge.fml.loading.moddiscovery.ExplodedDirectoryLocator
 net.minecraftforge.fml.loading.moddiscovery.MinecraftLocator
 net.minecraftforge.fml.loading.moddiscovery.ClasspathLocator
+net.minecraftforge.fml.loading.moddiscovery.JarInJarDependencyLocator

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -205,6 +205,12 @@ set -- \
         org.gradle.wrapper.GradleWrapperMain \
         "$@"
 
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
 # Use "xargs" to parse quoted args.
 #
 # With -n1 it outputs one arg per line, with the quotes and backslashes removed.

gradlew.bat

@@ -14,7 +14,7 @@
 @rem limitations under the License.
 @rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +25,7 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,7 +40,7 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -75,13 +75,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal

javafmllanguage/build.gradle

@@ -10,7 +10,7 @@ apply plugin: 'org.javamodularity.moduleplugin'
 dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
 
 dependencies {
-    compileOnly("org.jetbrains:annotations:${JETBRAINS_ANNOTATIONS_VERSION}")
+    compileOnly('org.jetbrains:annotations:21.0.1')
     implementation(project(':fmlloader'))
     implementation(project(':fmlcore'))
 }

javafmllanguage/src/main/java/net/minecraftforge/fml/javafmlmod/FMLModContainer.java

@@ -18,15 +18,14 @@ import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.ModFileScanData;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.Marker;
-import org.apache.logging.log4j.MarkerManager;
 
 import java.util.Optional;
 
+import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
+
 public class FMLModContainer extends ModContainer
 {
     private static final Logger LOGGER = LogManager.getLogger();
-    private static final Marker LOADING = MarkerManager.getMarker("LOADING");
     private final ModFileScanData scanResults;
     private final IEventBus eventBus;
     private Object modInstance;

l4jManifest.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> 
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!--The ID below indicates application support for Windows Vista -->
+      <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />
+      <!--The ID below indicates application support for Windows 7 -->
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
+      <!--The ID below indicates application support for Windows 8 -->
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+      <!--The ID below indicates application support for Windows 8.1 -->
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+      <!--The ID below indicates application supprort for Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+    </application>
+  </compatibility>
+
+  <!-- following stuff is so the EXE doesnt ask for admin access -->
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges>
+        <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+</assembly>

lowcodelanguage/src/main/java/net/minecraftforge/fml/lowcodemod/LowCodeModContainer.java

@@ -5,14 +5,14 @@
 
 package net.minecraftforge.fml.lowcodemod;
 
-import com.mojang.logging.LogUtils;
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.fml.IExtensionPoint;
 import net.minecraftforge.fml.ModContainer;
 import net.minecraftforge.fml.event.IModBusEvent;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.ModFileScanData;
-import org.slf4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.util.Objects;
 
@@ -20,7 +20,7 @@ import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
 
 public class LowCodeModContainer extends ModContainer
 {
-    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final Logger LOGGER = LogManager.getLogger();
     private final ModFileScanData scanResults;
     private Object modInstance;
 

mclanguage/build.gradle

@@ -10,7 +10,7 @@ apply plugin: 'org.javamodularity.moduleplugin'
 dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
 
 dependencies {
-    compileOnly("org.jetbrains:annotations:${JETBRAINS_ANNOTATIONS_VERSION}")
+    compileOnly('org.jetbrains:annotations:21.0.1')
     implementation(project(':fmlloader'))
     implementation(project(':fmlcore'))
 }

mdk/README.txt

@@ -16,14 +16,14 @@ Step 1: Open your command-line and browse to the folder where you extracted the
 
 Step 2: You're left with a choice.
 If you prefer to use Eclipse:
-1. Run the following command: `gradlew genEclipseRuns` (`./gradlew genEclipseRuns` if you are on Mac/Linux)
+1. Run the following command: `./gradlew genEclipseRuns`
 2. Open Eclipse, Import > Existing Gradle Project > Select Folder 
    or run `gradlew eclipse` to generate the project.
 
 If you prefer to use IntelliJ:
 1. Open IDEA, and import project.
 2. Select your build.gradle file and have it import.
-3. Run the following command: `gradlew genIntellijRuns` (`./gradlew genIntellijRuns` if you are on Mac/Linux)
+3. Run the following command: `./gradlew genIntellijRuns`
 4. Refresh the Gradle Project in IDEA if required.
 
 If at any point you are missing libraries in your IDE, or you've run into problems you can 
@@ -40,7 +40,7 @@ https://github.com/MinecraftForge/MCPConfig/blob/master/Mojang.md
 
 Additional Resources: 
 =========================
-Community Documentation: http://mcforge.readthedocs.io/en/latest/gettingstarted/  
-LexManos' Install Video: https://www.youtube.com/watch?v=8VEdtQLuLO0  
-Forge Forum: https://forums.minecraftforge.net/  
-Forge Discord: https://discord.gg/UvedJ9m  
+Community Documentation: https://docs.minecraftforge.net/en/1.18.x/gettingstarted/
+LexManos' Install Video: https://youtu.be/8VEdtQLuLO0
+Forge Forums: https://forums.minecraftforge.net/
+Forge Discord: https://discord.minecraftforge.net/

mdk/build.gradle

@@ -1,12 +1,16 @@
 plugins {
     id 'eclipse'
+    id 'idea'
     id 'maven-publish'
-    id 'net.minecraftforge.gradle' version '5.+'
+    id 'net.minecraftforge.gradle' version '[6.0,6.2)'
 }
 
-version = '1.0'
-group = 'com.yourname.modid' // http://maven.apache.org/guides/mini/guide-naming-conventions.html
-archivesBaseName = 'modid'
+version = mod_version
+group = mod_group_id
+
+base {
+    archivesName = mod_id
+}
 
 // Mojang ships Java 17 to end users in 1.18+, so your mod should target Java 17.
 java.toolchain.languageVersion = JavaLanguageVersion.of(17)
@@ -26,14 +30,36 @@ minecraft {
     //
     // Use non-default mappings at your own risk. They may not always work.
     // Simply re-run your setup task after changing the mappings to update your workspace.
-    mappings channel: '@MAPPING_CHANNEL@', version: '@MAPPING_VERSION@'
+    mappings channel: mapping_channel, version: mapping_version
 
-    // accessTransformer = file('src/main/resources/META-INF/accesstransformer.cfg') // Currently, this location cannot be changed from the default.
+    // When true, this property will have all Eclipse/IntelliJ IDEA run configurations run the "prepareX" task for the given run configuration before launching the game.
+    // In most cases, it is not necessary to enable.
+    // enableEclipsePrepareRuns = true
+    // enableIdeaPrepareRuns = true
+
+    // This property allows configuring Gradle's ProcessResources task(s) to run on IDE output locations before launching the game.
+    // It is REQUIRED to be set to true for this template to function.
+    // See https://docs.gradle.org/current/dsl/org.gradle.language.jvm.tasks.ProcessResources.html
+    copyIdeResources = true
+
+    // When true, this property will add the folder name of all declared run configurations to generated IDE run configurations.
+    // The folder name can be set on a run configuration using the "folderName" property.
+    // By default, the folder name of a run configuration is the name of the Gradle project containing it.
+    // generateRunFolders = true
+
+    // This property enables access transformers for use in development.
+    // They will be applied to the Minecraft artifact.
+    // The access transformer file can be anywhere in the project.
+    // However, it must be at "META-INF/accesstransformer.cfg" in the final mod jar to be loaded by Forge.
+    // This default location is a best practice to automatically put the file in the right place in the final jar.
+    // See https://docs.minecraftforge.net/en/latest/advanced/accesstransformers/ for more information.
+    // accessTransformer = file('src/main/resources/META-INF/accesstransformer.cfg')
 
     // Default run configurations.
     // These can be tweaked, removed, or duplicated as needed.
     runs {
-        client {
+        // applies to all the run configs below
+        configureEach {
             workingDirectory project.file('run')
 
             // Recommended logging data for a userdev environment
@@ -49,75 +75,38 @@ minecraft {
             property 'forge.logging.console.level', 'debug'
 
             // Comma-separated list of namespaces to load gametests from. Empty = all namespaces.
-            property 'forge.enabledGameTestNamespaces', 'examplemod'
+            property 'forge.enabledGameTestNamespaces', mod_id
 
             mods {
-                examplemod {
+                "${mod_id}" {
                     source sourceSets.main
                 }
             }
         }
 
-        server {
-            workingDirectory project.file('run')
-
-            property 'forge.logging.markers', 'REGISTRIES'
-
-            property 'forge.logging.console.level', 'debug'
-
+        client {
             // Comma-separated list of namespaces to load gametests from. Empty = all namespaces.
-            property 'forge.enabledGameTestNamespaces', 'examplemod'
+            property 'forge.enabledGameTestNamespaces', mod_id
+        }
 
-            mods {
-                examplemod {
-                    source sourceSets.main
-                }
-            }
+        server {
+            property 'forge.enabledGameTestNamespaces', mod_id
+            args '--nogui'
         }
 
         // This run config launches GameTestServer and runs all registered gametests, then exits.
         // By default, the server will crash when no gametests are provided.
         // The gametest system is also enabled by default for other run configs under the /test command.
         gameTestServer {
-            workingDirectory project.file('run')
-
-            // Recommended logging data for a userdev environment
-            // The markers can be added/remove as needed separated by commas.
-            // "SCAN": For mods scan.
-            // "REGISTRIES": For firing of registry events.
-            // "REGISTRYDUMP": For getting the contents of all registries.
-            property 'forge.logging.markers', 'REGISTRIES'
-
-            // Recommended logging level for the console
-            // You can set various levels here.
-            // Please read: https://stackoverflow.com/questions/2031163/when-to-use-the-different-log-levels
-            property 'forge.logging.console.level', 'debug'
-
-            // Comma-separated list of namespaces to load gametests from. Empty = all namespaces.
-            property 'forge.enabledGameTestNamespaces', 'examplemod'
-
-            mods {
-                examplemod {
-                    source sourceSets.main
-                }
-            }
+            property 'forge.enabledGameTestNamespaces', mod_id
         }
 
         data {
-            workingDirectory project.file('run')
-
-            property 'forge.logging.markers', 'REGISTRIES'
-
-            property 'forge.logging.console.level', 'debug'
+            // example of overriding the workingDirectory set in configureEach above
+            workingDirectory project.file('run-data')
 
             // Specify the modid for data generation, where to output the resulting resource, and where to look for existing resources.
-            args '--mod', 'examplemod', '--all', '--output', file('src/generated/resources/'), '--existing', file('src/main/resources/')
-
-            mods {
-                examplemod {
-                    source sourceSets.main
-                }
-            }
+            args '--mod', mod_id, '--all', '--output', file('src/generated/resources/'), '--existing', file('src/main/resources/')
         }
     }
 }
@@ -136,48 +125,73 @@ repositories {
 }
 
 dependencies {
-    // Specify the version of Minecraft to use. If this is any group other than 'net.minecraft', it is assumed
-    // that the dep is a ForgeGradle 'patcher' dependency, and its patches will be applied.
-    // The userdev artifact is a special name and will get all sorts of transformations applied to it.
-    minecraft '@FORGE_GROUP@:@FORGE_NAME@:@FORGE_VERSION@'
+    // Specify the version of Minecraft to use.
+    // Any artifact can be supplied so long as it has a "userdev" classifier artifact and is a compatible patcher artifact.
+    // The "userdev" classifier will be requested and setup by ForgeGradle.
+    // If the group id is "net.minecraft" and the artifact id is one of ["client", "server", "joined"],
+    // then special handling is done to allow a setup of a vanilla dependency without the use of an external repository.
+    minecraft "net.minecraftforge:forge:${minecraft_version}-${forge_version}"
 
     // Real mod deobf dependency examples - these get remapped to your current mappings
     // compileOnly fg.deobf("mezz.jei:jei-${mc_version}:${jei_version}:api") // Adds JEI API as a compile dependency
     // runtimeOnly fg.deobf("mezz.jei:jei-${mc_version}:${jei_version}") // Adds the full JEI mod as a runtime dependency
     // implementation fg.deobf("com.tterrag.registrate:Registrate:MC${mc_version}-${registrate_version}") // Adds registrate as a dependency
 
-    // Examples using mod jars from ./libs
+    // Example mod dependency using a mod jar from ./libs with a flat dir repository
+    // This maps to ./libs/coolmod-${mc_version}-${coolmod_version}.jar
+    // The group id is ignored when searching -- in this case, it is "blank"
     // implementation fg.deobf("blank:coolmod-${mc_version}:${coolmod_version}")
 
-    // For more info...
+    // For more info:
     // http://www.gradle.org/docs/current/userguide/artifact_dependencies_tutorial.html
     // http://www.gradle.org/docs/current/userguide/dependency_management.html
 }
 
-// Example for how to get properties into the manifest for reading at runtime.
-jar {
-    manifest {
-        attributes([
-                "Specification-Title"     : "examplemod",
-                "Specification-Vendor"    : "examplemodsareus",
-                "Specification-Version"   : "1", // We are version 1 of ourselves
-                "Implementation-Title"    : project.name,
-                "Implementation-Version"  : project.jar.archiveVersion,
-                "Implementation-Vendor"   : "examplemodsareus",
-                "Implementation-Timestamp": new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
-        ])
+// This block of code expands all declared replace properties in the specified resource targets.
+// A missing property will result in an error. Properties are expanded using ${} Groovy notation.
+// When "copyIdeResources" is enabled, this will also run before the game launches in IDE environments.
+// See https://docs.gradle.org/current/dsl/org.gradle.language.jvm.tasks.ProcessResources.html
+tasks.named('processResources', ProcessResources).configure {
+    var replaceProperties = [
+            minecraft_version: minecraft_version, minecraft_version_range: minecraft_version_range,
+            forge_version: forge_version, forge_version_range: forge_version_range,
+            loader_version_range: loader_version_range,
+            mod_id: mod_id, mod_name: mod_name, mod_license: mod_license, mod_version: mod_version,
+            mod_authors: mod_authors, mod_description: mod_description,
+    ]
+    inputs.properties replaceProperties
+
+    filesMatching(['META-INF/mods.toml', 'pack.mcmeta']) {
+        expand replaceProperties + [project: project]
     }
 }
 
-// Example configuration to allow publishing using the maven-publish plugin
-// This is the preferred method to reobfuscate your jar file
-jar.finalizedBy('reobfJar')
-// However if you are in a multi-project build, dev time needs unobfed jar files, so you can delay the obfuscation until publishing by doing
-// publish.dependsOn('reobfJar')
+// Example for how to get properties into the manifest for reading at runtime.
+tasks.named('jar', Jar).configure {
+    manifest {
+        attributes([
+                'Specification-Title'     : mod_id,
+                'Specification-Vendor'    : mod_authors,
+                'Specification-Version'   : '1', // We are version 1 of ourselves
+                'Implementation-Title'    : project.name,
+                'Implementation-Version'  : project.jar.archiveVersion,
+                'Implementation-Vendor'   : mod_authors,
+                'Implementation-Timestamp': new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
+        ])
+    }
+
+    // This is the preferred method to reobfuscate your jar file
+    finalizedBy 'reobfJar'
+}
+
+// However if you are in a multi-project build, dev time needs unobfed jar files, so you can delay the obfuscation until publishing by doing:
+// tasks.named('publish').configure {
+//     dependsOn 'reobfJar'
+// }
 
 publishing {
     publications {
-        mavenJava(MavenPublication) {
+        register('mavenJava', MavenPublication) {
             artifact jar
         }
     }