Start work on porting 0.7.4 over

Signed-off-by: shedaniel <daniel@shedaniel.me>

42 files changed, 1214 insertions, 811 deletions

diff --git a/build.gradle b/build.gradle
index c377e0ef..73226e3a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -91,7 +91,7 @@ dependencies {
 
 	// tinyfile management
 	implementation ('dev.architectury:tiny-remapper:1.1.0')
-	implementation ('dev.architectury:mappings-layers-core:1.3.8')
+	implementation ('dev.architectury:mappings-layers-core:1.4.9')
 	implementation ('net.fabricmc:tiny-mappings-parser:0.3.0+build.17')
 
 	implementation 'net.fabricmc:access-widener:1.1.0'
@@ -135,6 +135,7 @@ dependencies {
 	compileOnly('org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.21')
 
 	// Forge patches
+	implementation ('net.minecraftforge:installertools:1.2.0')
 	implementation ('net.minecraftforge:binarypatcher:1.1.1')
 	implementation ('org.cadixdev:lorenz:0.5.3')
 	implementation ('org.cadixdev:lorenz-asm:0.5.3')
diff --git a/forge-runtime/.gitignore b/forge-runtime/.gitignore
deleted file mode 100644
index 31ecb657..00000000
--- a/forge-runtime/.gitignore
+++ /dev/null
@@ -1,6 +0,0 @@
-# Ignore everything
-/*
-
-!/src
-!/build.gradle
-!/.gitignore
diff --git a/forge-runtime/build.gradle b/forge-runtime/build.gradle
deleted file mode 100644
index 388db8e3..00000000
--- a/forge-runtime/build.gradle
+++ /dev/null
@@ -1,93 +0,0 @@
-plugins {
-	id 'java'
-	id 'maven-publish'
-	id 'checkstyle'
-	id 'com.github.johnrengelman.shadow' version '7.0.0'
-	id "com.diffplug.spotless"
-}
-
-group = rootProject.group
-archivesBaseName = 'architectury-loom-forge-runtime'
-version = rootProject.version
-
-sourceCompatibility = JavaVersion.VERSION_1_8
-targetCompatibility = JavaVersion.VERSION_1_8
-
-configurations {
-	include
-	compileOnly.extendsFrom include
-}
-
-tasks.withType(JavaCompile).configureEach {
-	it.options.encoding = "UTF-8"
-	it.options.release = 8
-}
-
-repositories {
-	mavenCentral()
-	maven { url "https://maven.fabricmc.net/" }
-	maven {
-		url "https://maven.minecraftforge.net/"
-		content {
-			excludeGroupByRegex "org\\.eclipse\\.?.*"
-		}
-	}
-}
-
-dependencies {
-	// shadowed
-	include ('net.fabricmc:tiny-mappings-parser:0.3.0+build.17')
-
-	// guaranteed to be there at runtime
-	compileOnly ('cpw.mods:modlauncher:6.1.3')
-	compileOnly ('org.spongepowered:mixin:0.8.2')
-	compileOnly ('com.google.code.gson:gson:2.8.6')
-	compileOnly ('com.google.guava:guava:21.0')
-	compileOnly ('org.apache.logging.log4j:log4j-api:2.11.2')
-}
-
-jar {
-	archiveClassifier = "slim"
-}
-
-shadowJar {
-	archiveClassifier = ""
-	configurations = [project.configurations.include]
-	relocate "net.fabricmc.mapping", "dev.architectury.loom.forgeruntime.shadow.mapping"
-	relocate "net.fabricmc.mappings", "dev.architectury.loom.forgeruntime.shadow.mappings"
-}
-
-assemble.dependsOn shadowJar
-
-spotless {
-	java {
-		licenseHeaderFile(rootProject.file("HEADER")).yearSeparator("-")
-		targetExclude("**/loom/forgeruntime/mixin/MixinIntermediaryDevRemapper.java")
-	}
-}
-
-checkstyle {
-	configFile = rootProject.checkstyle.configFile
-	toolVersion = rootProject.checkstyle.toolVersion
-}
-
-publishing {
-	publications {
-		maven(MavenPublication) {
-			artifactId = 'architectury-loom-forge-runtime'
-			shadow.component it
-		}
-	}
-
-	repositories {
-		if (System.getenv("MAVEN_PASS") != null) {
-			maven {
-				url = "https://deploy.shedaniel.me/"
-				credentials {
-					username = "shedaniel"
-					password = System.getenv("MAVEN_PASS")
-				}
-			}
-		}
-	}
-}
diff --git a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/YarnNamingService.java b/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/YarnNamingService.java
deleted file mode 100644
index 6a291de3..00000000
--- a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/YarnNamingService.java
+++ /dev/null
@@ -1,128 +0,0 @@
-/*
- * This file is part of fabric-loom, licensed under the MIT License (MIT).
- *
- * Copyright (c) 2020-2021 FabricMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package dev.architectury.loom.forgeruntime;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.UncheckedIOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.AbstractMap;
-import java.util.Map;
-import java.util.Optional;
-import java.util.function.BiFunction;
-import java.util.function.Predicate;
-
-import cpw.mods.modlauncher.api.INameMappingService;
-
-import net.fabricmc.mapping.tree.TinyMappingFactory;
-import net.fabricmc.mapping.tree.TinyTree;
-
-public class YarnNamingService implements INameMappingService {
-	private static final String PATH_TO_MAPPINGS = "fabric.yarnWithSrg.path";
-	private TinyTree mappings = null;
-
-	@Override
-	public String mappingName() {
-		return "srgtoyarn";
-	}
-
-	@Override
-	public String mappingVersion() {
-		return "1";
-	}
-
-	@Override
-	public Map.Entry<String, String> understanding() {
-		return new AbstractMap.SimpleImmutableEntry<>("srg", "mcp");
-	}
-
-	@Override
-	public BiFunction<Domain, String, String> namingFunction() {
-		return this::remap;
-	}
-
-	private TinyTree getMappings() {
-		if (mappings != null) {
-			return mappings;
-		}
-
-		String pathStr = System.getProperty(PATH_TO_MAPPINGS);
-		if (pathStr == null) throw new RuntimeException("Missing system property '" + PATH_TO_MAPPINGS + "'!");
-		Path path = Paths.get(pathStr);
-
-		try (BufferedReader reader = Files.newBufferedReader(path)) {
-			mappings = TinyMappingFactory.loadWithDetection(reader);
-		} catch (IOException e) {
-			throw new UncheckedIOException(e);
-		}
-
-		return mappings;
-	}
-
-	private String remap(Domain domain, String name) {
-		TinyTree mappings = getMappings();
-
-		switch (domain) {
-		case CLASS:
-			boolean dot = name.contains(".");
-			return find(mappings.getClasses(), def -> maybeReplace(dot, def.getName("srg"), '/', '.').equals(name))
-					.map(def -> maybeReplace(dot, def.getName("named"), '/', '.'))
-					.orElse(name);
-		case METHOD:
-			return mappings.getClasses().stream()
-					.flatMap(def -> def.getMethods().stream())
-					.filter(def -> def.getName("srg").equals(name))
-					.findAny()
-					.map(def -> def.getName("named"))
-					.orElse(name);
-		case FIELD:
-			return mappings.getClasses().stream()
-					.flatMap(def -> def.getFields().stream())
-					.filter(def -> def.getName("srg").equals(name))
-					.findAny()
-					.map(def -> def.getName("named"))
-					.orElse(name);
-		default:
-			return name;
-		}
-	}
-
-	// From CollectionUtil
-	private static <E> Optional<E> find(Iterable<? extends E> collection, Predicate<? super E> filter) {
-		for (E e : collection) {
-			if (filter.test(e)) {
-				return Optional.of(e);
-			}
-		}
-
-		return Optional.empty();
-	}
-
-	private static String maybeReplace(boolean run, String s, char from, char to) {
-		return run ? s.replace(from, to) : s;
-	}
-}
diff --git a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/ForgeLoomMixinRemapperInjectorService.java b/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/ForgeLoomMixinRemapperInjectorService.java
deleted file mode 100644
index 8b1839fb..00000000
--- a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/ForgeLoomMixinRemapperInjectorService.java
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * This file is part of fabric-loom, licensed under the MIT License (MIT).
- *
- * Copyright (c) 2021 FabricMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package dev.architectury.loom.forgeruntime.mixin;
-
-import java.io.BufferedReader;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.Collections;
-import java.util.List;
-import java.util.Objects;
-import java.util.Set;
-
-import cpw.mods.modlauncher.api.IEnvironment;
-import cpw.mods.modlauncher.api.ITransformationService;
-import cpw.mods.modlauncher.api.ITransformer;
-import cpw.mods.modlauncher.api.IncompatibleEnvironmentException;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-import org.spongepowered.asm.mixin.MixinEnvironment;
-
-import net.fabricmc.mapping.tree.TinyMappingFactory;
-import net.fabricmc.mapping.tree.TinyTree;
-
-public class ForgeLoomMixinRemapperInjectorService implements ITransformationService {
-	private static final Logger LOGGER = LogManager.getLogger("ForgeLoomRemapperInjector");
-
-	@Override
-	public String name() {
-		return "ForgeLoomMixinRemapperInjector";
-	}
-
-	@Override
-	public void initialize(IEnvironment environment) {
-	}
-
-	@Override
-	public void beginScanning(IEnvironment environment) {
-		LOGGER.debug("We will be injecting our remapper.");
-
-		try {
-			MixinEnvironment.getDefaultEnvironment().getRemappers().add(new MixinIntermediaryDevRemapper(Objects.requireNonNull(resolveMappings()), "intermediary", "named"));
-			LOGGER.debug("We have successfully injected our remapper.");
-		} catch (Exception e) {
-			LOGGER.debug("We have failed to inject our remapper.", e);
-		}
-	}
-
-	@Override
-	public void onLoad(IEnvironment env, Set<String> otherServices) throws IncompatibleEnvironmentException {
-	}
-
-	@Override
-	public List<ITransformer> transformers() {
-		return Collections.emptyList();
-	}
-
-	private static TinyTree resolveMappings() {
-		try {
-			String srgNamedProperty = System.getProperty("mixin.forgeloom.inject.mappings.srg-named");
-			Path path = Paths.get(srgNamedProperty);
-
-			try (BufferedReader reader = Files.newBufferedReader(path)) {
-				return TinyMappingFactory.loadWithDetection(reader);
-			}
-		} catch (Throwable throwable) {
-			throwable.printStackTrace();
-			return null;
-		}
-	}
-}
diff --git a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/MixinIntermediaryDevRemapper.java b/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/MixinIntermediaryDevRemapper.java
deleted file mode 100644
index f331a9ca..00000000
--- a/forge-runtime/src/main/java/dev/architectury/loom/forgeruntime/mixin/MixinIntermediaryDevRemapper.java
+++ /dev/null
@@ -1,233 +0,0 @@
-/*
- * Copyright 2016 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package dev.architectury.loom.forgeruntime.mixin;
-
-import java.util.ArrayDeque;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Queue;
-import java.util.Set;
-
-import org.spongepowered.asm.mixin.transformer.ClassInfo;
-
-import net.fabricmc.mapping.tree.ClassDef;
-import net.fabricmc.mapping.tree.Descriptored;
-import net.fabricmc.mapping.tree.TinyTree;
-import net.fabricmc.mapping.util.MixinRemapper;
-
-public class MixinIntermediaryDevRemapper extends MixinRemapper {
-	private static final String ambiguousName = "<ambiguous>"; // dummy value for ambiguous mappings - needs querying with additional owner and/or desc info
-
-	private final Set<String> allPossibleClassNames = new HashSet<>();
-	private final Map<String, String> nameFieldLookup = new HashMap<>();
-	private final Map<String, String> nameMethodLookup = new HashMap<>();
-	private final Map<String, String> nameDescFieldLookup = new HashMap<>();
-	private final Map<String, String> nameDescMethodLookup = new HashMap<>();
-
-	public MixinIntermediaryDevRemapper(TinyTree mappings, String from, String to) {
-		super(mappings, from, to);
-
-		for (ClassDef classDef : mappings.getClasses()) {
-			allPossibleClassNames.add(classDef.getName(from));
-			allPossibleClassNames.add(classDef.getName(to));
-
-			putMemberInLookup(from, to, classDef.getFields(), nameFieldLookup, nameDescFieldLookup);
-			putMemberInLookup(from, to, classDef.getMethods(), nameMethodLookup, nameDescMethodLookup);
-		}
-	}
-
-	private <T extends Descriptored> void putMemberInLookup(String from, String to, Collection<T> descriptored, Map<String, String> nameMap, Map<String, String> nameDescMap) {
-		for (T field : descriptored) {
-			String nameFrom = field.getName(from);
-			String descFrom = field.getDescriptor(from);
-			String nameTo = field.getName(to);
-
-			String prev = nameMap.putIfAbsent(nameFrom, nameTo);
-
-			if (prev != null && prev != ambiguousName && !prev.equals(nameTo)) {
-				nameDescMap.put(nameFrom, ambiguousName);
-			}
-
-			String key = getNameDescKey(nameFrom, descFrom);
-			prev = nameDescMap.putIfAbsent(key, nameTo);
-
-			if (prev != null && prev != ambiguousName && !prev.equals(nameTo)) {
-				nameDescMap.put(key, ambiguousName);
-			}
-		}
-	}
-
-	private void throwAmbiguousLookup(String type, String name, String desc) {
-		throw new RuntimeException("Ambiguous Mixin: " + type + " lookup " + name + " " + desc + " is not unique");
-	}
-
-	private String mapMethodNameInner(String owner, String name, String desc) {
-		String result = super.mapMethodName(owner, name, desc);
-
-		if (result.equals(name)) {
-			String otherClass = unmap(owner);
-			return super.mapMethodName(otherClass, name, unmapDesc(desc));
-		} else {
-			return result;
-		}
-	}
-
-	private String mapFieldNameInner(String owner, String name, String desc) {
-		String result = super.mapFieldName(owner, name, desc);
-
-		if (result.equals(name)) {
-			String otherClass = unmap(owner);
-			return super.mapFieldName(otherClass, name, unmapDesc(desc));
-		} else {
-			return result;
-		}
-	}
-
-	@Override
-	public String mapMethodName(String owner, String name, String desc) {
-		// handle unambiguous values early
-		if (owner == null || allPossibleClassNames.contains(owner)) {
-			String newName;
-
-			if (desc == null) {
-				newName = nameMethodLookup.get(name);
-			} else {
-				newName = nameDescMethodLookup.get(getNameDescKey(name, desc));
-			}
-
-			if (newName != null) {
-				if (newName == ambiguousName) {
-					if (owner == null) {
-						throwAmbiguousLookup("method", name, desc);
-					}
-				} else {
-					return newName;
-				}
-			} else if (owner == null) {
-				return name;
-			} else {
-				// FIXME: this kind of namespace mixing shouldn't happen..
-				// TODO: this should not repeat more than once
-				String unmapOwner = unmap(owner);
-				String unmapDesc = unmapDesc(desc);
-
-				if (!unmapOwner.equals(owner) || !unmapDesc.equals(desc)) {
-					return mapMethodName(unmapOwner, name, unmapDesc);
-				} else {
-					// take advantage of the fact allPossibleClassNames
-					// and nameDescLookup cover all sets; if none are present,
-					// we don't have a mapping for it.
-					return name;
-				}
-			}
-		}
-
-		Queue<ClassInfo> classInfos = new ArrayDeque<>();
-		classInfos.add(ClassInfo.forName(owner));
-
-		while (!classInfos.isEmpty()) {
-			ClassInfo c = classInfos.remove();
-			String ownerO = unmap(c.getName());
-			String s;
-
-			if (!(s = mapMethodNameInner(ownerO, name, desc)).equals(name)) {
-				return s;
-			}
-
-			if (!c.getSuperName().startsWith("java/")) {
-				ClassInfo cSuper = c.getSuperClass();
-
-				if (cSuper != null) {
-					classInfos.add(cSuper);
-				}
-			}
-
-			for (String itf : c.getInterfaces()) {
-				if (itf.startsWith("java/")) {
-					continue;
-				}
-
-				ClassInfo cItf = ClassInfo.forName(itf);
-
-				if (cItf != null) {
-					classInfos.add(cItf);
-				}
-			}
-		}
-
-		return name;
-	}
-
-	@Override
-	public String mapFieldName(String owner, String name, String desc) {
-		// handle unambiguous values early
-		if (owner == null || allPossibleClassNames.contains(owner)) {
-			String newName = nameDescFieldLookup.get(getNameDescKey(name, desc));
-
-			if (newName != null) {
-				if (newName == ambiguousName) {
-					if (owner == null) {
-						throwAmbiguousLookup("field", name, desc);
-					}
-				} else {
-					return newName;
-				}
-			} else if (owner == null) {
-				return name;
-			} else {
-				// FIXME: this kind of namespace mixing shouldn't happen..
-				// TODO: this should not repeat more than once
-				String unmapOwner = unmap(owner);
-				String unmapDesc = unmapDesc(desc);
-
-				if (!unmapOwner.equals(owner) || !unmapDesc.equals(desc)) {
-					return mapFieldName(unmapOwner, name, unmapDesc);
-				} else {
-					// take advantage of the fact allPossibleClassNames
-					// and nameDescLookup cover all sets; if none are present,
-					// we don't have a mapping for it.
-					return name;
-				}
-			}
-		}
-
-		ClassInfo c = ClassInfo.forName(map(owner));
-
-		while (c != null) {
-			String nextOwner = unmap(c.getName());
-			String s;
-
-			if (!(s = mapFieldNameInner(nextOwner, name, desc)).equals(name)) {
-				return s;
-			}
-
-			if (c.getSuperName().startsWith("java/")) {
-				break;
-			}
-
-			c = c.getSuperClass();
-		}
-
-		return name;
-	}
-
-	private static String getNameDescKey(String name, String descriptor) {
-		return name + ";;" + descriptor;
-	}
-}
diff --git a/forge-runtime/src/main/java/mcp/MethodsReturnNonnullByDefault.java b/forge-runtime/src/main/java/mcp/MethodsReturnNonnullByDefault.java
deleted file mode 100644
index bfa2d691..00000000
--- a/forge-runtime/src/main/java/mcp/MethodsReturnNonnullByDefault.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * This file is part of fabric-loom, licensed under the MIT License (MIT).
- *
- * Copyright (c) 2020-2021 FabricMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package mcp;
-
-/**
- * A dummy class, required for some Forge classes to load
- * because {@code MethodsReturnNonnullByDefault} in MCP has runtime retention.
- *
- * @deprecated Don't use this in your mods. JetBrains annotations are there for you.
- */
-@Deprecated
-public @interface MethodsReturnNonnullByDefault {
-}
diff --git a/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.INameMappingService b/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.INameMappingService
deleted file mode 100644
index ec41d220..00000000
--- a/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.INameMappingService
+++ /dev/null
@@ -1 +0,0 @@
-dev.architectury.loom.forgeruntime.YarnNamingService
diff --git a/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.ITransformationService b/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.ITransformationService
deleted file mode 100644
index 679794d7..00000000
--- a/forge-runtime/src/main/resources/META-INF/services/cpw.mods.modlauncher.api.ITransformationService
+++ /dev/null
@@ -1 +0,0 @@
-dev.architectury.loom.forgeruntime.mixin.ForgeLoomMixinRemapperInjectorService
\ No newline at end of file
diff --git a/settings.gradle b/settings.gradle
index 0b542936..0dfb5fc9 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,3 +1,2 @@
 rootProject.name = "architectury-loom"
 include "bootstrap"
-include "forge-runtime"
diff --git a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
index 6c3541e9..63ad8974 100644
--- a/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
+++ b/src/main/java/net/fabricmc/loom/LoomGradleExtension.java
@@ -122,6 +122,16 @@ public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 		return getDependencyManager().getProvider(McpConfigProvider.class);
 	}
 
+	@Override
+	default boolean isForgeAndOfficial() {
+		return isForge() && getMcpConfigProvider().isOfficial();
+	}
+
+	@Override
+	default boolean isForgeAndNotOfficial() {
+		return isForge() && !getMcpConfigProvider().isOfficial();
+	}
+
 	default SrgProvider getSrgProvider() {
 		return getDependencyManager().getProvider(SrgProvider.class);
 	}
diff --git a/src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java b/src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java
index 3d39cd51..ab5db4a8 100644
--- a/src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java
+++ b/src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java
@@ -195,6 +195,10 @@ public interface LoomGradleExtensionAPI {
 		return getPlatform().get() == ModPlatform.FORGE;
 	}
 
+	boolean isForgeAndOfficial();
+
+	boolean isForgeAndNotOfficial();
+
 	boolean supportsInclude();
 
 	void setGenerateSrgTiny(Boolean generateSrgTiny);
diff --git a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
index e6589da5..d23072f6 100644
--- a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
+++ b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
@@ -83,8 +83,9 @@ public final class CompileConfiguration {
 			extension.createLazyConfiguration(Constants.Configurations.FORGE_USERDEV).configure(configuration -> configuration.setTransitive(false));
 			extension.createLazyConfiguration(Constants.Configurations.FORGE_INSTALLER).configure(configuration -> configuration.setTransitive(false));
 			extension.createLazyConfiguration(Constants.Configurations.FORGE_UNIVERSAL).configure(configuration -> configuration.setTransitive(false));
-			extension.createLazyConfiguration(Constants.Configurations.FORGE_DEPENDENCIES).configure(configuration -> configuration.setTransitive(false));
+			extension.createLazyConfiguration(Constants.Configurations.FORGE_DEPENDENCIES);
 			extension.createLazyConfiguration(Constants.Configurations.FORGE_NAMED).configure(configuration -> configuration.setTransitive(false));
+			extension.createLazyConfiguration(Constants.Configurations.FORGE_EXTRA).configure(configuration -> configuration.setTransitive(false));
 			extension.createLazyConfiguration(Constants.Configurations.MCP_CONFIG).configure(configuration -> configuration.setTransitive(false));
 
 			extendsFrom(Constants.Configurations.MINECRAFT_DEPENDENCIES, Constants.Configurations.FORGE_DEPENDENCIES, project);
@@ -93,6 +94,10 @@ public final class CompileConfiguration {
 			extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_NAMED, project);
 			extendsFrom(JavaPlugin.TEST_COMPILE_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_NAMED, project);
 			extendsFrom(JavaPlugin.TEST_RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_NAMED, project);
+			extendsFrom(JavaPlugin.COMPILE_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_EXTRA, project);
+			extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_EXTRA, project);
+			extendsFrom(JavaPlugin.TEST_COMPILE_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_EXTRA, project);
+			extendsFrom(JavaPlugin.TEST_RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.FORGE_EXTRA, project);
 		}
 
 		if (extension.supportsInclude()) {
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
index a8d77353..e630939c 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
@@ -24,21 +24,15 @@
 
 package net.fabricmc.loom.configuration.ide;
 
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.HashMap;
 import java.util.Objects;
-import java.util.UUID;
 import java.util.function.Consumer;
-import java.util.function.Supplier;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
@@ -132,23 +126,6 @@ public class RunConfig {
 
 		runConfig.mainClass = "net.fabricmc.devlaunchinjector.Main";
 		runConfig.vmArgs = "-Dfabric.dli.config=" + encodeEscaped(extension.getFiles().getDevLauncherConfig().getAbsolutePath()) + " -Dfabric.dli.env=" + environment.toLowerCase();
-
-		if (extension.isForge()) {
-			List<String> modClasses = new ArrayList<>();
-
-			for (Supplier<SourceSet> sourceSetSupplier : extension.getForgeLocalMods()) {
-				SourceSet sourceSet = sourceSetSupplier.get();
-				String sourceSetName = sourceSet.getName() + "_" + UUID.randomUUID().toString().replace("-", "").substring(0, 7);
-
-				Stream.concat(
-						Stream.of(sourceSet.getOutput().getResourcesDir().getAbsolutePath()),
-						StreamSupport.stream(sourceSet.getOutput().getClassesDirs().spliterator(), false)
-								.map(File::getAbsolutePath)
-				).map(s -> sourceSetName + "%%" + s).collect(Collectors.toCollection(() -> modClasses));
-			}
-
-			runConfig.envVariables.put("MOD_CLASSES", String.join(File.pathSeparator, modClasses));
-		}
 	}
 
 	// Turns camelCase/PascalCase into Capital Case
@@ -162,6 +139,7 @@ public class RunConfig {
 	}
 
 	public static RunConfig runConfig(Project project, RunConfigSettings settings) {
+		settings.evaluateNow();
 		LoomGradleExtension extension = LoomGradleExtension.get(project);
 		String name = settings.getName();
 
@@ -195,6 +173,7 @@ public class RunConfig {
 		}
 
 		RunConfig runConfig = new RunConfig();
+		runConfig.envVariables.putAll(settings.envVariables);
 		runConfig.configName = configName;
 		populate(project, extension, runConfig, environment);
 		runConfig.ideaModuleName = getIdeaModuleName(project, sourceSet);
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
index 28f2f2f6..c7c0792f 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfigSettings.java
@@ -28,6 +28,7 @@ import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
@@ -36,6 +37,7 @@ import org.gradle.api.Named;
 import org.gradle.api.Project;
 import org.gradle.api.plugins.JavaPluginConvention;
 import org.gradle.api.tasks.SourceSet;
+import org.jetbrains.annotations.ApiStatus;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.util.Constants;
@@ -96,6 +98,8 @@ public final class RunConfigSettings implements Named {
 
 	private final Project project;
 	private final LoomGradleExtension extension;
+	public final Map<String, String> envVariables = new HashMap<>();
+	private List<Runnable> evaluateLater = new ArrayList<>();
 
 	public RunConfigSettings(Project project, String baseName) {
 		this.baseName = baseName;
@@ -107,6 +111,20 @@ public final class RunConfigSettings implements Named {
 		runDir("run");
 	}
 
+	@ApiStatus.Internal
+	public void evaluateLater(Runnable runnable) {
+		this.evaluateLater.add(runnable);
+	}
+
+	@ApiStatus.Internal
+	public void evaluateNow() {
+		for (Runnable runnable : this.evaluateLater) {
+			runnable.run();
+		}
+
+		this.evaluateLater.clear();
+	}
+
 	public Project getProject() {
 		return project;
 	}
diff --git a/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java b/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
index db815e94..52006eaa 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/SetupIntelijRunConfigs.java
@@ -46,13 +46,13 @@ public class SetupIntelijRunConfigs {
 		}
 
 		try {
-			generate(project);
+			generate(project, false);
 		} catch (IOException e) {
 			throw new RuntimeException("Failed to generate run configs", e);
 		}
 	}
 
-	private static void generate(Project project) throws IOException {
+	public static void generate(Project project, boolean override) throws IOException {
 		Project rootProject = project.getRootProject();
 		LoomGradleExtension extension = LoomGradleExtension.get(project);
 
@@ -82,6 +82,10 @@ public class SetupIntelijRunConfigs {
 			File runConfigs = new File(runConfigsDir, name + projectPath + ".xml");
 			String runConfigXml = config.fromDummy("idea_run_config_template.xml");
 
+			if (runConfigs.exists() && override) {
+				runConfigs.delete();
+			}
+
 			if (!runConfigs.exists()) {
 				FileUtils.writeStringToFile(runConfigs, runConfigXml, StandardCharsets.UTF_8);
 			}
diff --git a/src/main/java/net/fabricmc/loom/configuration/launch/LaunchProviderSettings.java b/src/main/java/net/fabricmc/loom/configuration/launch/LaunchProviderSettings.java
index 3a0c8eca..0ac814b5 100644
--- a/src/main/java/net/fabricmc/loom/configuration/launch/LaunchProviderSettings.java
+++ b/src/main/java/net/fabricmc/loom/configuration/launch/LaunchProviderSettings.java
@@ -33,11 +33,13 @@ import java.util.Map;
 
 import org.gradle.api.Named;
 import org.gradle.api.Project;
+import org.jetbrains.annotations.ApiStatus;
 
 public class LaunchProviderSettings implements Named {
 	private final String name;
 	private List<Map.Entry<String, String>> properties = new ArrayList<>();
 	private List<String> arguments = new ArrayList<>();
+	private List<Runnable> evaluateLater = new ArrayList<>();
 
 	public LaunchProviderSettings(Project project, String name) {
 		this.name = name;
@@ -48,6 +50,20 @@ public class LaunchProviderSettings implements Named {
 		return name;
 	}
 
+	@ApiStatus.Internal
+	public void evaluateLater(Runnable runnable) {
+		this.evaluateLater.add(runnable);
+	}
+
+	@ApiStatus.Internal
+	public void evaluateNow() {
+		for (Runnable runnable : this.evaluateLater) {
+			runnable.run();
+		}
+
+		this.evaluateLater.clear();
+	}
+
 	public void arg(String argument) {
 		this.arguments.add(argument);
 	}
diff --git a/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java b/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
index b7b37506..46d2e2ae 100644
--- a/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
+++ b/src/main/java/net/fabricmc/loom/configuration/mods/ModProcessor.java
@@ -164,7 +164,7 @@ public class ModProcessor {
 
 		remapper.readClassPathAsync(mc);
 
-		if (extension.isForge()) {
+		if (extension.isForgeAndNotOfficial()) {
 			remapper.readClassPathAsync(mappedProvider.getForgeSrgJar().toPath());
 		}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/LaunchProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/LaunchProvider.java
index 9fc55c0f..af90c480 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/LaunchProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/LaunchProvider.java
@@ -60,31 +60,21 @@ public class LaunchProvider extends DependencyProvider {
 				.property("log4j.configurationFile", getAllLog4JConfigFiles())
 
 				.property("client", "java.library.path", getExtension().getMinecraftProvider().nativesDir().getAbsolutePath())
-				.property("client", "org.lwjgl.librarypath", getExtension().getMinecraftProvider().nativesDir().getAbsolutePath())
+				.property("client", "org.lwjgl.librarypath", getExtension().getMinecraftProvider().nativesDir().getAbsolutePath());
 
-				.argument("client", "--assetIndex")
-				.argument("client", getExtension().getMinecraftProvider().getVersionInfo().assetIndex().fabricId(getExtension().getMinecraftProvider().minecraftVersion()))
-				.argument("client", "--assetsDir")
-				.argument("client", new File(getDirectories().getUserCache(), "assets").getAbsolutePath());
+		if (!getExtension().isForge()) {
+			launchConfig
+					.argument("client", "--assetIndex")
+					.argument("client", getExtension().getMinecraftProvider().getVersionInfo().assetIndex().fabricId(getExtension().getMinecraftProvider().minecraftVersion()))
+					.argument("client", "--assetsDir")
+					.argument("client", new File(getDirectories().getUserCache(), "assets").getAbsolutePath());
+		}
 
 		if (getExtension().isForge()) {
 			launchConfig
 					// Should match YarnNamingService.PATH_TO_MAPPINGS in forge-runtime
 					.property("fabric.yarnWithSrg.path", getExtension().getMappingsProvider().tinyMappingsWithSrg.toAbsolutePath().toString())
 
-					.argument("--fml.mcVersion")
-					.argument(getExtension().getMinecraftProvider().minecraftVersion())
-					.argument("--fml.forgeVersion")
-					.argument(getExtension().getForgeProvider().getVersion().getForgeVersion())
-
-					.argument("client", "--launchTarget")
-					.argument("client", "fmluserdevclient")
-
-					.argument("server", "--launchTarget")
-					.argument("server", "fmluserdevserver")
-
-					.argument("data", "--launchTarget")
-					.argument("data", "fmluserdevdata")
 					.argument("data", "--all")
 					.argument("data", "--mod")
 					.argument("data", String.join(",", getExtension().getDataGenMods()))
@@ -109,7 +99,18 @@ public class LaunchProvider extends DependencyProvider {
 			}
 		}
 
+		addDependency(Constants.Dependencies.DEV_LAUNCH_INJECTOR + Constants.Dependencies.Versions.DEV_LAUNCH_INJECTOR, Constants.Configurations.LOOM_DEVELOPMENT_DEPENDENCIES);
+		addDependency(Constants.Dependencies.TERMINAL_CONSOLE_APPENDER + Constants.Dependencies.Versions.TERMINAL_CONSOLE_APPENDER, Constants.Configurations.LOOM_DEVELOPMENT_DEPENDENCIES);
+		addDependency(Constants.Dependencies.JETBRAINS_ANNOTATIONS + Constants.Dependencies.Versions.JETBRAINS_ANNOTATIONS, JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME);
+
+		if (getExtension().isForge()) {
+			addDependency(Constants.Dependencies.FORGE_RUNTIME + Constants.Dependencies.Versions.FORGE_RUNTIME, Constants.Configurations.FORGE_EXTRA);
+			addDependency(Constants.Dependencies.JAVAX_ANNOTATIONS + Constants.Dependencies.Versions.JAVAX_ANNOTATIONS, JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME);
+		}
+
 		for (LaunchProviderSettings settings : getExtension().getLaunchConfigs()) {
+			settings.evaluateNow();
+
 			for (String argument : settings.getArguments()) {
 				launchConfig.argument(settings.getName(), argument);
 			}
@@ -129,16 +130,6 @@ public class LaunchProvider extends DependencyProvider {
 		writeLog4jConfig();
 		FileUtils.writeStringToFile(getDirectories().getDevLauncherConfig(), launchConfig.asString(), StandardCharsets.UTF_8);
 
-		addDependency(Constants.Dependencies.DEV_LAUNCH_INJECTOR + Constants.Dependencies.Versions.DEV_LAUNCH_INJECTOR, Constants.Configurations.LOOM_DEVELOPMENT_DEPENDENCIES);
-		addDependency(Constants.Dependencies.TERMINAL_CONSOLE_APPENDER + Constants.Dependencies.Versions.TERMINAL_CONSOLE_APPENDER, Constants.Configurations.LOOM_DEVELOPMENT_DEPENDENCIES);
-		addDependency(Constants.Dependencies.JETBRAINS_ANNOTATIONS + Constants.Dependencies.Versions.JETBRAINS_ANNOTATIONS, JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME);
-
-		if (getExtension().isForge()) {
-			addDependency(Constants.Dependencies.FORGE_RUNTIME + Constants.Dependencies.Versions.FORGE_RUNTIME, JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME);
-			addDependency(Constants.Dependencies.FORGE_RUNTIME + Constants.Dependencies.Versions.FORGE_RUNTIME, JavaPlugin.RUNTIME_ONLY_CONFIGURATION_NAME);
-			addDependency(Constants.Dependencies.JAVAX_ANNOTATIONS + Constants.Dependencies.Versions.JAVAX_ANNOTATIONS, JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME);
-		}
-
 		postPopulationScheduler.accept(this::writeRemapClassPath);
 	}
 
@@ -178,7 +169,7 @@ public class LaunchProvider extends DependencyProvider {
 
 		remapClasspath.add(getExtension().getMinecraftMappedProvider().getIntermediaryJar());
 
-		if (getExtension().isForge()) {
+		if (getExtension().isForgeAndNotOfficial()) {
 			remapClasspath.add(getExtension().getMinecraftMappedProvider().getForgeIntermediaryJar());
 		}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
index 518398df..2440f526 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/FieldMigratedMappingsProvider.java
@@ -103,7 +103,7 @@ public class FieldMigratedMappingsProvider extends MappingsProviderImpl {
 
 	@Override
 	protected String createMappingsIdentifier(String mappingsName, String version, String classifier) {
-		return super.createMappingsIdentifier(mappingsName, version, classifier) + "-forge-" + getExtension().getPatchProvider().forgeVersion;
+		return super.createMappingsIdentifier(mappingsName, version, classifier) + "-forge-" + getExtension().getForgeProvider().getVersion().getCombined();
 	}
 
 	@Override
@@ -116,7 +116,7 @@ public class FieldMigratedMappingsProvider extends MappingsProviderImpl {
 		if (getExtension().shouldGenerateSrgTiny()) {
 			if (Files.notExists(rawTinyMappingsWithSrg) || isRefreshDeps()) {
 				// Merge tiny mappings with srg
-				SrgMerger.mergeSrg(getExtension().getSrgProvider().getSrg().toPath(), rawTinyMappings, rawTinyMappingsWithSrg, true);
+				SrgMerger.mergeSrg(this::getMojmapSrgFileIfPossible, getRawSrgFile(), rawTinyMappings, rawTinyMappingsWithSrg, true);
 			}
 		}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeProvider.java
index 50f6f82c..f9e1b9ef 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeProvider.java
@@ -55,10 +55,13 @@ public class ForgeProvider extends DependencyProvider {
 	}
 
 	public static final class ForgeVersion {
+		private final String combined;
 		private final String minecraftVersion;
 		private final String forgeVersion;
 
 		public ForgeVersion(String combined) {
+			this.combined = combined;
+
 			if (combined == null) {
 				this.minecraftVersion = "NO_VERSION";
 				this.forgeVersion = "NO_VERSION";
@@ -76,6 +79,10 @@ public class ForgeProvider extends DependencyProvider {
 			}
 		}
 
+		public String getCombined() {
+			return combined;
+		}
+
 		public String getMinecraftVersion() {
 			return minecraftVersion;
 		}
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeUserdevProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeUserdevProvider.java
index 26add71e..2dd91d9d 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeUserdevProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/ForgeUserdevProvider.java
@@ -25,6 +25,7 @@
 package net.fabricmc.loom.configuration.providers.forge;
 
 import java.io.File;
+import java.io.IOException;
 import java.io.Reader;
 import java.net.URI;
 import java.nio.file.FileSystem;
@@ -32,19 +33,46 @@ import java.nio.file.FileSystems;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
 import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 import com.google.common.collect.ImmutableMap;
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import org.gradle.api.Project;
+import org.gradle.api.artifacts.Dependency;
+import org.gradle.api.artifacts.ModuleDependency;
+import org.gradle.api.artifacts.transform.InputArtifact;
+import org.gradle.api.artifacts.transform.TransformAction;
+import org.gradle.api.artifacts.transform.TransformOutputs;
+import org.gradle.api.artifacts.transform.TransformParameters;
+import org.gradle.api.artifacts.type.ArtifactTypeDefinition;
+import org.gradle.api.attributes.Attribute;
+import org.gradle.api.file.FileSystemLocation;
+import org.gradle.api.provider.Provider;
+import org.gradle.api.tasks.SourceSet;
 
 import net.fabricmc.loom.configuration.DependencyProvider;
+import net.fabricmc.loom.configuration.ide.RunConfigSettings;
+import net.fabricmc.loom.configuration.launch.LaunchProviderSettings;
 import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.DependencyDownloader;
+import net.fabricmc.loom.util.FileSystemUtil;
 
 public class ForgeUserdevProvider extends DependencyProvider {
 	private File userdevJar;
+	private JsonObject json;
+	private Consumer<Runnable> postPopulationScheduler;
 
 	public ForgeUserdevProvider(Project project) {
 		super(project);
@@ -52,6 +80,18 @@ public class ForgeUserdevProvider extends DependencyProvider {
 
 	@Override
 	public void provide(DependencyInfo dependency, Consumer<Runnable> postPopulationScheduler) throws Exception {
+		this.postPopulationScheduler = postPopulationScheduler;
+		Attribute<Boolean> transformed = Attribute.of("architectury-loom-forge-dependencies-transformed", Boolean.class);
+
+		getProject().getDependencies().registerTransform(RemoveNameProvider.class, spec -> {
+			spec.getFrom().attribute(transformed, false);
+			spec.getTo().attribute(transformed, true);
+		});
+
+		for (ArtifactTypeDefinition type : getProject().getDependencies().getArtifactTypes()) {
+			type.getAttributes().attribute(transformed, false);
+		}
+
 		userdevJar = new File(getDirectories().getProjectPersistentCache(), "forge-" + dependency.getDependency().getVersion() + "-userdev.jar");
 
 		Path configJson = getDirectories()
@@ -68,8 +108,6 @@ public class ForgeUserdevProvider extends DependencyProvider {
 			}
 		}
 
-		JsonObject json;
-
 		try (Reader reader = Files.newBufferedReader(configJson)) {
 			json = new Gson().fromJson(reader, JsonObject.class);
 		}
@@ -79,19 +117,199 @@ public class ForgeUserdevProvider extends DependencyProvider {
 		addDependency(json.get("universal").getAsString(), Constants.Configurations.FORGE_UNIVERSAL);
 
 		for (JsonElement lib : json.get("libraries").getAsJsonArray()) {
+			Dependency dep = null;
+
 			if (lib.getAsString().startsWith("org.spongepowered:mixin:")) {
 				if (getExtension().isUseFabricMixin()) {
-					addDependency("net.fabricmc:sponge-mixin:0.8.2+build.24", Constants.Configurations.FORGE_DEPENDENCIES);
-					continue;
+					dep = addDependency("net.fabricmc:sponge-mixin:0.8.2+build.24", Constants.Configurations.FORGE_DEPENDENCIES);
 				}
 			}
 
-			addDependency(lib.getAsString(), Constants.Configurations.FORGE_DEPENDENCIES);
+			if (dep == null) {
+				dep = addDependency(lib.getAsString(), Constants.Configurations.FORGE_DEPENDENCIES);
+			}
+
+			if (lib.getAsString().split(":").length < 4) {
+				((ModuleDependency) dep).attributes(attributes -> {
+					attributes.attribute(transformed, true);
+				});
+			}
 		}
 
 		// TODO: Read launch configs from the JSON too
 		// TODO: Should I copy the patches from here as well?
 		//       That'd require me to run the "MCP environment" fully up to merging.
+		for (Map.Entry<String, JsonElement> entry : json.getAsJsonObject("runs").entrySet()) {
+			LaunchProviderSettings launchSettings = getExtension().getLaunchConfigs().findByName(entry.getKey());
+			RunConfigSettings settings = getExtension().getRunConfigs().findByName(entry.getKey());
+			JsonObject value = entry.getValue().getAsJsonObject();
+
+			if (launchSettings != null) {
+				launchSettings.evaluateLater(() -> {
+					if (value.has("args")) {
+						launchSettings.arg(StreamSupport.stream(value.getAsJsonArray("args").spliterator(), false)
+								.map(JsonElement::getAsString)
+								.map(this::processTemplates)
+								.collect(Collectors.toList()));
+					}
+
+					if (value.has("props")) {
+						for (Map.Entry<String, JsonElement> props : value.getAsJsonObject("props").entrySet()) {
+							String string = processTemplates(props.getValue().getAsString());
+
+							launchSettings.property(props.getKey(), string);
+						}
+					}
+				});
+			}
+
+			if (settings != null) {
+				settings.evaluateLater(() -> {
+					settings.defaultMainClass(value.getAsJsonPrimitive("main").getAsString());
+					settings.vmArgs(StreamSupport.stream(value.getAsJsonArray("jvmArgs").spliterator(), false)
+							.map(JsonElement::getAsString)
+							.map(this::processTemplates)
+							.collect(Collectors.toList()));
+					for (Map.Entry<String, JsonElement> env : value.getAsJsonObject("env").entrySet()) {
+						String string = processTemplates(env.getValue().getAsString());
+
+						settings.envVariables.put(env.getKey(), string);
+					}
+				});
+			}
+		}
+	}
+
+	public abstract static class RemoveNameProvider implements TransformAction<TransformParameters.None> {
+		@InputArtifact
+		public abstract Provider<FileSystemLocation> getInput();
+
+		@Override
+		public void transform(TransformOutputs outputs) {
+			try {
+				File input = getInput().get().getAsFile();
+				//architectury-loom-forge-dependencies-transformed
+				File output = outputs.file(input.getName() + "-alfd-transformed.jar");
+				Files.copy(input.toPath(), output.toPath(), StandardCopyOption.REPLACE_EXISTING);
+
+				try (FileSystemUtil.FileSystemDelegate fs = FileSystemUtil.getJarFileSystem(output, false)) {
+					Path path = fs.get().getPath("META-INF/services/cpw.mods.modlauncher.api.INameMappingService");
+					Files.deleteIfExists(path);
+				}
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+	}
+
+	public String processTemplates(String string) {
+		if (string.startsWith("{")) {
+			String key = string.substring(1, string.length() - 1);
+
+			// TODO: Look into ways to not hardcode
+			if (key.equals("runtime_classpath")) {
+				string = runtimeClasspath().stream()
+						.map(File::getAbsolutePath)
+						.collect(Collectors.joining(File.pathSeparator));
+			} else if (key.equals("minecraft_classpath")) {
+				string = minecraftClasspath().stream()
+						.map(File::getAbsolutePath)
+						.collect(Collectors.joining(File.pathSeparator));
+			} else if (key.equals("runtime_classpath_file")) {
+				Path path = getDirectories().getProjectPersistentCache().toPath().resolve("forge_runtime_classpath.txt");
+
+				postPopulationScheduler.accept(() -> {
+					try {
+						Files.writeString(path, runtimeClasspath().stream()
+										.map(File::getAbsolutePath)
+										.collect(Collectors.joining("\n")),
+								StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+					} catch (IOException e) {
+						throw new RuntimeException(e);
+					}
+				});
+
+				string = path.toAbsolutePath().toString();
+			} else if (key.equals("minecraft_classpath_file")) {
+				Path path = getDirectories().getProjectPersistentCache().toPath().resolve("forge_minecraft_classpath.txt");
+
+				postPopulationScheduler.accept(() -> {
+					try {
+						Files.writeString(path, minecraftClasspath().stream()
+										.map(File::getAbsolutePath)
+										.collect(Collectors.joining("\n")),
+								StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+					} catch (IOException e) {
+						throw new RuntimeException(e);
+					}
+				});
+
+				string = path.toAbsolutePath().toString();
+			} else if (key.equals("asset_index")) {
+				string = getExtension().getMinecraftProvider().getVersionInfo().assetIndex().fabricId(getExtension().getMinecraftProvider().minecraftVersion());
+			} else if (key.equals("assets_root")) {
+				string = new File(getDirectories().getUserCache(), "assets").getAbsolutePath();
+			} else if (key.equals("natives")) {
+				string = getMinecraftProvider().nativesDir().getAbsolutePath();
+			} else if (key.equals("source_roots")) {
+				List<String> modClasses = new ArrayList<>();
+
+				for (Supplier<SourceSet> sourceSetSupplier : getExtension().getForgeLocalMods()) {
+					SourceSet sourceSet = sourceSetSupplier.get();
+					String sourceSetName = sourceSet.getName() + "_" + UUID.randomUUID().toString().replace("-", "").substring(0, 7);
+
+					Stream.concat(
+							Stream.of(sourceSet.getOutput().getResourcesDir().getAbsolutePath()),
+							StreamSupport.stream(sourceSet.getOutput().getClassesDirs().spliterator(), false)
+									.map(File::getAbsolutePath)
+					).map(s -> sourceSetName + "%%" + s).collect(Collectors.toCollection(() -> modClasses));
+				}
+
+				string = String.join(File.pathSeparator, modClasses);
+			} else if (json.has(key)) {
+				JsonElement element = json.get(key);
+
+				if (element.isJsonArray()) {
+					string = StreamSupport.stream(element.getAsJsonArray().spliterator(), false)
+							.map(JsonElement::getAsString)
+							.flatMap(str -> {
+								if (str.contains(":")) {
+									return DependencyDownloader.download(getProject(), str, false, false).getFiles().stream()
+											.map(File::getAbsolutePath)
+											.filter(dep -> !dep.contains("bootstraplauncher")); // TODO: Hack
+								}
+
+								return Stream.of(str);
+							})
+							.collect(Collectors.joining(File.pathSeparator));
+				} else {
+					string = element.toString();
+				}
+			} else {
+				getProject().getLogger().warn("Unrecognized template! " + string);
+			}
+		}
+
+		return string;
+	}
+
+	private Set<File> runtimeClasspath() {
+		// Should we actually include the runtime classpath here? Forge doesn't seem to be using this property anyways
+		Set<File> mcLibs = DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_DEPENDENCIES), true);
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.MINECRAFT_DEPENDENCIES), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_EXTRA), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.MINECRAFT_NAMED), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_NAMED), false));
+		return mcLibs;
+	}
+
+	private Set<File> minecraftClasspath() {
+		Set<File> mcLibs = DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_DEPENDENCIES), true);
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.MINECRAFT_DEPENDENCIES), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_EXTRA), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.MINECRAFT_NAMED), false));
+		mcLibs.addAll(DependencyDownloader.resolveFiles(getProject().getConfigurations().getByName(Constants.Configurations.FORGE_NAMED), false));
+		return mcLibs;
 	}
 
 	public File getUserdevJar() {
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/McpConfigProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/McpConfigProvider.java
index 78375240..c8d7b0c0 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/McpConfigProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/McpConfigProvider.java
@@ -24,19 +24,33 @@
 
 package net.fabricmc.loom.configuration.providers.forge;
 
+import java.io.BufferedWriter;
 import java.io.File;
+import java.io.IOException;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
+import java.nio.file.StandardOpenOption;
 import java.util.function.Consumer;
 
+import com.google.gson.Gson;
+import com.google.gson.JsonObject;
+import org.apache.commons.io.IOUtils;
 import org.gradle.api.Project;
+import org.zeroturnaround.zip.ZipUtil;
 
 import net.fabricmc.loom.configuration.DependencyProvider;
 import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.FileSystemUtil;
 
 public class McpConfigProvider extends DependencyProvider {
 	private File mcp;
+	private Path configJson;
+	private Path mappings;
+	private Boolean official;
+	private String mappingsPath;
 
 	public McpConfigProvider(Project project) {
 		super(project);
@@ -46,25 +60,63 @@ public class McpConfigProvider extends DependencyProvider {
 	public void provide(DependencyInfo dependency, Consumer<Runnable> postPopulationScheduler) throws Exception {
 		init(dependency.getDependency().getVersion());
 
-		if (mcp.exists() && !isRefreshDeps()) {
-			return; // No work for us to do here
-		}
-
 		Path mcpZip = dependency.resolveFile().orElseThrow(() -> new RuntimeException("Could not resolve MCPConfig")).toPath();
 
-		if (!mcp.exists() || isRefreshDeps()) {
+		if (!mcp.exists() || !Files.exists(configJson) || isRefreshDeps()) {
 			Files.copy(mcpZip, mcp.toPath(), StandardCopyOption.REPLACE_EXISTING);
+
+			try (FileSystemUtil.FileSystemDelegate fs = FileSystemUtil.getJarFileSystem(mcp, false)) {
+				Files.copy(fs.get().getPath("config.json"), configJson, StandardCopyOption.REPLACE_EXISTING);
+			}
 		}
+
+		JsonObject json;
+
+		try (Reader reader = Files.newBufferedReader(configJson)) {
+			json = new Gson().fromJson(reader, JsonObject.class);
+		}
+
+		official = json.has("official") && json.getAsJsonPrimitive("official").getAsBoolean();
+		mappingsPath = json.get("data").getAsJsonObject().get("mappings").getAsString();
 	}
 
-	private void init(String version) {
-		mcp = new File(getDirectories().getUserCache(), "mcp-" + version + ".zip");
+	private void init(String version) throws IOException {
+		File dir = getMinecraftProvider().dir("mcp/" + version);
+		mcp = new File(dir, "mcp.zip");
+		configJson = dir.toPath().resolve("mcp-config.json");
+		mappings = dir.toPath().resolve("mcp-config-mappings.txt");
+
+		if (isRefreshDeps()) {
+			Files.deleteIfExists(mappings);
+		}
+	}
+
+	public Path getMappings() {
+		if (Files.notExists(mappings)) {
+			if (!ZipUtil.handle(getMcp(), getMappingsPath(), (in, zipEntry) -> {
+				try (BufferedWriter writer = Files.newBufferedWriter(mappings, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+					IOUtils.copy(in, writer, StandardCharsets.UTF_8);
+				}
+			})) {
+				throw new IllegalStateException("Failed to find mappings '" + getMappingsPath() + "' in " + getMcp().getAbsolutePath() + "!");
+			}
+		}
+
+		return mappings;
 	}
 
 	public File getMcp() {
 		return mcp;
 	}
 
+	public boolean isOfficial() {
+		return official;
+	}
+
+	public String getMappingsPath() {
+		return mappingsPath;
+	}
+
 	@Override
 	public String getTargetConfig() {
 		return Constants.Configurations.MCP_CONFIG;
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
index e4d60816..ae988155 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/MinecraftPatchedProvider.java
@@ -29,7 +29,6 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.io.UncheckedIOException;
@@ -55,47 +54,63 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.jar.Attributes;
 import java.util.jar.Manifest;
+import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
 import com.google.common.base.Preconditions;
-import com.google.common.base.Predicates;
 import com.google.common.base.Stopwatch;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.hash.Hashing;
 import com.google.common.io.ByteSource;
-import com.google.gson.JsonParser;
 import de.oceanlabs.mcp.mcinjector.adaptors.ParameterAnnotationFixer;
+import dev.architectury.mappingslayers.api.mutable.MutableClassDef;
+import dev.architectury.mappingslayers.api.mutable.MutableMethodDef;
+import dev.architectury.mappingslayers.api.mutable.MutableTinyTree;
+import dev.architectury.mappingslayers.api.utils.MappingsUtils;
 import dev.architectury.tinyremapper.InputTag;
 import dev.architectury.tinyremapper.OutputConsumerPath;
 import dev.architectury.tinyremapper.TinyRemapper;
 import net.minecraftforge.binarypatcher.ConsoleTool;
-import org.apache.commons.io.IOUtils;
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.output.NullOutputStream;
 import org.gradle.api.Project;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.logging.LogLevel;
 import org.gradle.api.logging.Logger;
+import org.gradle.api.logging.configuration.ShowStacktrace;
 import org.gradle.api.plugins.JavaPluginConvention;
 import org.gradle.api.tasks.SourceSet;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.ClassNode;
 import org.zeroturnaround.zip.ZipUtil;
 
+import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.configuration.DependencyProvider;
+import net.fabricmc.loom.configuration.providers.MinecraftProvider;
 import net.fabricmc.loom.configuration.providers.MinecraftProviderImpl;
+import net.fabricmc.loom.configuration.providers.mappings.GradleMappingContext;
+import net.fabricmc.loom.configuration.providers.mappings.MappingNamespace;
+import net.fabricmc.loom.configuration.providers.mappings.mojmap.MojangMappingLayer;
+import net.fabricmc.loom.configuration.providers.mappings.mojmap.MojangMappingsSpec;
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftMappedProvider;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.DependencyDownloader;
 import net.fabricmc.loom.util.FileSystemUtil;
+import net.fabricmc.loom.util.MappingsProviderVerbose;
 import net.fabricmc.loom.util.ThreadingUtils;
 import net.fabricmc.loom.util.TinyRemapperMappingsHelper;
 import net.fabricmc.loom.util.function.FsPathConsumer;
 import net.fabricmc.loom.util.srg.InnerClassRemapper;
 import net.fabricmc.loom.util.srg.SpecialSourceExecutor;
+import net.fabricmc.loom.util.srg.Tsrg2Utils;
 import net.fabricmc.mapping.tree.TinyTree;
+import net.fabricmc.mappingio.MappingVisitor;
 
 public class MinecraftPatchedProvider extends DependencyProvider {
 	private static final String LOOM_PATCH_VERSION_KEY = "Loom-Patch-Version";
@@ -115,11 +130,14 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 	// Step 5: Remap Patched AT & Forge to Official (global or project)
 	private File minecraftMergedPatchedJar;
 	private File forgeMergedJar;
+	private File minecraftClientExtra;
 
 	private File projectAtHash;
 	private Set<File> projectAts = new HashSet<>();
 	private boolean atDirty = false;
 	private boolean filesDirty = false;
+	private Path mcpConfigMappings;
+	private Path[] mergedMojangTsrg2Files;
 
 	public MinecraftPatchedProvider(Project project) {
 		super(project);
@@ -161,34 +179,29 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 		MinecraftProviderImpl minecraftProvider = getExtension().getMinecraftProvider();
 		PatchProvider patchProvider = getExtension().getPatchProvider();
 		String minecraftVersion = minecraftProvider.minecraftVersion();
-		String patchId = "forge-" + patchProvider.forgeVersion;
-
-		if (getExtension().isUseFabricMixin()) {
-			patchId += "-fabric-mixin";
-		}
+		String patchId = "forge-" + getExtension().getForgeProvider().getVersion().getCombined();
 
 		minecraftProvider.setJarSuffix(patchId);
 
-		File globalCache = getDirectories().getUserCache();
+		File globalCache = getMinecraftProvider().dir("forge/" + getExtension().getForgeProvider().getVersion().getCombined());
 		File cache = usesProjectCache() ? getDirectories().getProjectPersistentCache() : globalCache;
-		File globalDir = new File(globalCache, patchId);
-		File projectDir = new File(cache, patchId);
-		globalDir.mkdirs();
+		File projectDir = new File(cache, "forge/" + getExtension().getForgeProvider().getVersion().getCombined());
 		projectDir.mkdirs();
 
-		minecraftClientSrgJar = new File(globalCache, "minecraft-" + minecraftVersion + "-client-srg.jar");
-		minecraftServerSrgJar = new File(globalCache, "minecraft-" + minecraftVersion + "-server-srg.jar");
-		minecraftClientPatchedSrgJar = new File(globalDir, "client-srg-patched.jar");
-		minecraftServerPatchedSrgJar = new File(globalDir, "server-srg-patched.jar");
-		minecraftMergedPatchedSrgJar = new File(globalDir, "merged-srg-patched.jar");
-		forgeMergedJar = new File(globalDir, "forge-official.jar");
+		minecraftClientSrgJar = new File(globalCache, "minecraft-client-srg.jar");
+		minecraftServerSrgJar = new File(globalCache, "minecraft-server-srg.jar");
+		minecraftClientPatchedSrgJar = new File(globalCache, "client-srg-patched.jar");
+		minecraftServerPatchedSrgJar = new File(globalCache, "server-srg-patched.jar");
+		minecraftMergedPatchedSrgJar = new File(globalCache, "merged-srg-patched.jar");
+		forgeMergedJar = getExtension().isForgeAndOfficial() ? null : new File(globalCache, "forge-official.jar");
 		minecraftMergedPatchedSrgAtJar = new File(projectDir, "merged-srg-at-patched.jar");
 		minecraftMergedPatchedJar = new File(projectDir, "merged-patched.jar");
+		minecraftClientExtra = new File(globalCache, "forge-client-extra.jar");
 
-		if (isRefreshDeps() || Stream.of(getGlobalCaches()).anyMatch(Predicates.not(File::exists))
+		if (isRefreshDeps() || Stream.of(getGlobalCaches()).anyMatch(((Predicate<File>) File::exists).negate())
 						|| !isPatchedJarUpToDate(minecraftMergedPatchedJar)) {
 			cleanAllCache();
-		} else if (atDirty || Stream.of(getProjectCache()).anyMatch(Predicates.not(File::exists))) {
+		} else if (atDirty || Stream.of(getProjectCache()).anyMatch(((Predicate<File>) File::exists).negate())) {
 			cleanProjectCache();
 		}
 	}
@@ -213,14 +226,21 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 	}
 
 	private File[] getGlobalCaches() {
-		return new File[] {
+		File[] files = {
 				minecraftClientSrgJar,
 				minecraftServerSrgJar,
 				minecraftClientPatchedSrgJar,
 				minecraftServerPatchedSrgJar,
 				minecraftMergedPatchedSrgJar,
-				forgeMergedJar,
+				minecraftClientExtra,
 		};
+
+		if (forgeMergedJar != null) {
+			Arrays.copyOf(files, files.length + 1);
+			files[files.length - 1] = forgeMergedJar;
+		}
+
+		return files;
 	}
 
 	public void cleanProjectCache() {
@@ -270,7 +290,7 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 			accessTransformForge(getProject().getLogger());
 		}
 
-		if (!forgeMergedJar.exists()) {
+		if (forgeMergedJar != null && !forgeMergedJar.exists()) {
 			this.dirty = true;
 		}
 
@@ -278,10 +298,25 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 
 		if (dirty) {
 			remapPatchedJar(input, getProject().getLogger());
+
+			if (getExtension().isForgeAndOfficial()) {
+				fillClientExtraJar();
+			}
 		}
 
 		this.filesDirty = dirty;
 		this.dirty = false;
+
+		if (getExtension().isForgeAndOfficial()) {
+			addDependency(minecraftClientExtra, Constants.Configurations.FORGE_EXTRA);
+		}
+	}
+
+	private void fillClientExtraJar() throws IOException {
+		Files.deleteIfExists(minecraftClientExtra.toPath());
+		FileSystemUtil.getJarFileSystem(minecraftClientExtra, true).close();
+
+		copyNonClassFiles(getExtension().getMinecraftProvider().minecraftClientJar, minecraftClientExtra);
 	}
 
 	private TinyRemapper buildRemapper(Path input) throws IOException {
@@ -291,12 +326,16 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 				.logger(getProject().getLogger()::lifecycle)
 				.logUnknownInvokeDynamic(false)
 				.withMappings(TinyRemapperMappingsHelper.create(mappingsWithSrg, "srg", "official", true))
-				.withMappings(InnerClassRemapper.of(input, mappingsWithSrg, "srg", "official"))
+				.withMappings(InnerClassRemapper.of(InnerClassRemapper.readClassNames(input), mappingsWithSrg, "srg", "official"))
 				.renameInvalidLocals(true)
 				.rebuildSourceFilenames(true)
 				.fixPackageAccess(true)
 				.build();
 
+		if (getProject().getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) < 0) {
+			MappingsProviderVerbose.saveFile(remapper);
+		}
+
 		remapper.readClassPath(libraries);
 		remapper.prepareClasses();
 		return remapper;
@@ -309,39 +348,105 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 	}
 
 	private void createSrgJars(Logger logger) throws Exception {
-		McpConfigProvider mcpProvider = getExtension().getMcpConfigProvider();
-
 		MinecraftProviderImpl minecraftProvider = getExtension().getMinecraftProvider();
+		String dep = getExtension().isForgeAndOfficial() ? Constants.Dependencies.VIGNETTE + Constants.Dependencies.Versions.VIGNETTE
+				: Constants.Dependencies.SPECIAL_SOURCE + Constants.Dependencies.Versions.SPECIAL_SOURCE + ":shaded";
+		FileCollection classpath = DependencyDownloader.download(getProject(), dep, true, true);
+		produceSrgJar(getExtension().isForgeAndOfficial(), minecraftProvider.minecraftClientJar.toPath(), minecraftProvider.minecraftServerJar.toPath(), classpath);
+	}
 
-		String[] mappingsPath = {null};
+	private void produceSrgJar(boolean official, Path clientJar, Path serverJar, FileCollection classpath) throws IOException {
+		Path tmpSrg = getToSrgMappings();
+		Set<File> mcLibs = getProject().getConfigurations().getByName(Constants.Configurations.MINECRAFT_DEPENDENCIES).resolve();
 
-		if (!ZipUtil.handle(mcpProvider.getMcp(), "config.json", (in, zipEntry) -> {
-			mappingsPath[0] = JsonParser.parseReader(new InputStreamReader(in)).getAsJsonObject().get("data").getAsJsonObject().get("mappings").getAsString();
-		})) {
-			throw new IllegalStateException("Failed to find 'config.json' in " + mcpProvider.getMcp().getAbsolutePath() + "!");
+		ThreadingUtils.run(() -> {
+			Files.copy(SpecialSourceExecutor.produceSrgJar(getProject(), "client", classpath, clientJar, tmpSrg), minecraftClientSrgJar.toPath());
+		}, () -> {
+				Files.copy(SpecialSourceExecutor.produceSrgJar(getProject(), "server", classpath, serverJar, tmpSrg), minecraftServerSrgJar.toPath());
+			});
+	}
+
+	private Path getToSrgMappings() throws IOException {
+		if (getExtension().isForgeAndOfficial()) {
+			return getMergedMojangTsrg2(true);
+		} else {
+			return getExtension().getMcpConfigProvider().getMappings();
 		}
+	}
 
-		Path[] tmpSrg = {null};
+	private static void visitMojmap(MappingVisitor visitor, LoomGradleExtension extension) {
+		GradleMappingContext context = new GradleMappingContext(extension.getForgeProvider().getProject(), "tmp-mojmap");
+
+		try {
+			FileUtils.deleteDirectory(context.workingDirectory("/"));
+			MojangMappingLayer layer = new MojangMappingsSpec(() -> true).createLayer(context);
+			layer.visit(visitor);
+		} catch (IOException e) {
+			throw new UncheckedIOException(e);
+		} finally {
+			try {
+				FileUtils.deleteDirectory(context.workingDirectory("/"));
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+	}
 
-		if (!ZipUtil.handle(mcpProvider.getMcp(), mappingsPath[0], (in, zipEntry) -> {
-			tmpSrg[0] = Files.createTempFile(null, null);
+	public static Path getMojmapTsrg(LoomGradleExtension extension) throws IOException {
+		Path path = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg");
 
-			try (BufferedWriter writer = Files.newBufferedWriter(tmpSrg[0])) {
-				IOUtils.copy(in, writer, StandardCharsets.UTF_8);
+		if (Files.notExists(path)) {
+			try (BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+				Tsrg2Utils.writeTsrg(visitor -> visitMojmap(visitor, extension),
+						MappingNamespace.NAMED.stringValue(), false, writer);
 			}
-		})) {
-			throw new IllegalStateException("Failed to find mappings '" + mappingsPath[0] + "' in " + mcpProvider.getMcp().getAbsolutePath() + "!");
 		}
 
-		String atDependency = Constants.Dependencies.SPECIAL_SOURCE + Constants.Dependencies.Versions.SPECIAL_SOURCE + ":shaded";
-		// Do getFiles() to resolve it before multithreading it
-		FileCollection classpath = getProject().files(DependencyDownloader.download(getProject(), atDependency).getFiles());
+		return path;
+	}
 
-		ThreadingUtils.run(() -> {
-			Files.copy(SpecialSourceExecutor.produceSrgJar(getProject(), "client", classpath, minecraftProvider.minecraftClientJar.toPath(), tmpSrg[0]), minecraftClientSrgJar.toPath());
-		}, () -> {
-				Files.copy(SpecialSourceExecutor.produceSrgJar(getProject(), "server", classpath, minecraftProvider.minecraftServerJar.toPath(), tmpSrg[0]), minecraftServerSrgJar.toPath());
+	public static Path getMojmapTsrg2(LoomGradleExtension extension) throws IOException {
+		Path path = extension.getMinecraftProvider().dir("forge").toPath().resolve("mojmap.tsrg");
+
+		if (Files.notExists(path)) {
+			try (BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
+				Tsrg2Utils.writeTsrg2(visitor -> visitMojmap(visitor, extension), writer);
+			}
+		}
+
+		return path;
+	}
+
+	public Path getMergedMojangTsrg2(boolean hasParameters) throws IOException {
+		if (mergedMojangTsrg2Files == null) {
+			Path out = Files.createTempFile("merged-mojang-tsrg2", null);
+			Path outTrimmed = Files.createTempFile("merged-mojang-tsrg2-trimmed", null);
+			net.minecraftforge.installertools.ConsoleTool.main(new String[]{
+					"--task",
+					"MERGE_MAPPING",
+					"--left",
+					getExtension().getMcpConfigProvider().getMappings().toAbsolutePath().toString(),
+					"--right",
+					getMojmapTsrg(getExtension()).toAbsolutePath().toString(),
+					"--classes",
+					"--output",
+					out.toAbsolutePath().toString()
 			});
+
+			MutableTinyTree mappings = MappingsUtils.deserializeFromTsrg2(FileUtils.readFileToString(out.toFile(), StandardCharsets.UTF_8));
+
+			for (MutableClassDef classDef : mappings.getClassesMutable()) {
+				for (MutableMethodDef methodDef : classDef.getMethodsMutable()) {
+					methodDef.getParametersMutable().clear();
+				}
+			}
+
+			Files.writeString(outTrimmed, MappingsUtils.serializeToTsrg2(mappings), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+
+			mergedMojangTsrg2Files = new Path[]{out, outTrimmed};
+		}
+
+		return mergedMojangTsrg2Files[hasParameters ? 0 : 1];
 	}
 
 	private void fixParameterAnnotation(File jarFile) throws Exception {
@@ -378,6 +483,60 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 		getProject().getLogger().info(":fixing parameter annotations for " + jarFile.getAbsolutePath() + " in " + stopwatch);
 	}
 
+	private void deleteParameterNames(File jarFile) throws Exception {
+		getProject().getLogger().info(":deleting parameter names for " + jarFile.getAbsolutePath());
+		Stopwatch stopwatch = Stopwatch.createStarted();
+
+		try (FileSystem fs = FileSystems.newFileSystem(new URI("jar:" + jarFile.toURI()), ImmutableMap.of("create", false))) {
+			ThreadingUtils.TaskCompleter completer = ThreadingUtils.taskCompleter();
+			Pattern vignetteParameters = Pattern.compile("p_\\d+_");
+
+			for (Path file : (Iterable<? extends Path>) Files.walk(fs.getPath("/"))::iterator) {
+				if (!file.toString().endsWith(".class")) continue;
+
+				completer.add(() -> {
+					byte[] bytes = Files.readAllBytes(file);
+					ClassReader reader = new ClassReader(bytes);
+					ClassWriter writer = new ClassWriter(0);
+
+					reader.accept(new ClassVisitor(Opcodes.ASM9, writer) {
+						@Override
+						public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+							return new MethodVisitor(Opcodes.ASM9, super.visitMethod(access, name, descriptor, signature, exceptions)) {
+								@Override
+								public void visitParameter(String name, int access) {
+									if (vignetteParameters.matcher(name).matches()) {
+										super.visitParameter(null, access);
+									} else {
+										super.visitParameter(name, access);
+									}
+								}
+
+								@Override
+								public void visitLocalVariable(String name, String descriptor, String signature, Label start, Label end, int index) {
+									if (!vignetteParameters.matcher(name).matches()) {
+										super.visitLocalVariable(name, descriptor, signature, start, end, index);
+									}
+								}
+							};
+						}
+					}, 0);
+
+					byte[] out = writer.toByteArray();
+
+					if (!Arrays.equals(bytes, out)) {
+						Files.delete(file);
+						Files.write(file, out);
+					}
+				});
+			}
+
+			completer.complete();
+		}
+
+		getProject().getLogger().info(":deleting parameter names for " + jarFile.getAbsolutePath() + " in " + stopwatch);
+	}
+
 	private File getForgeJar() {
 		return getExtension().getForgeUniversalProvider().getForge();
 	}
@@ -453,8 +612,10 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 			spec.setClasspath(classpath);
 
 			// if running with INFO or DEBUG logging
-			if (getProject().getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) < 0) {
+			if (getProject().getGradle().getStartParameter().getShowStacktrace() != ShowStacktrace.INTERNAL_EXCEPTIONS
+						|| getProject().getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) < 0) {
 				spec.setStandardOutput(System.out);
+				spec.setErrorOutput(System.err);
 			} else {
 				spec.setStandardOutput(NullOutputStream.NULL_OUTPUT_STREAM);
 				spec.setErrorOutput(NullOutputStream.NULL_OUTPUT_STREAM);
@@ -529,7 +690,12 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 
 		ThreadingUtils.run(Environment.values(), environment -> {
 			copyMissingClasses(environment.srgJar.apply(this), environment.patchedSrgJar.apply(this));
-			fixParameterAnnotation(environment.patchedSrgJar.apply(this));
+
+			if (getExtension().isForgeAndNotOfficial()) {
+				fixParameterAnnotation(environment.patchedSrgJar.apply(this));
+			} else {
+				deleteParameterNames(environment.patchedSrgJar.apply(this));
+			}
 		});
 
 		logger.lifecycle(":patched jars in " + stopwatch.stop());
@@ -565,9 +731,12 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 		logger.lifecycle(":copying resources");
 
 		// Copy resources
-		MinecraftProviderImpl minecraftProvider = getExtension().getMinecraftProvider();
-		copyNonClassFiles(minecraftProvider.minecraftClientJar, minecraftMergedPatchedSrgJar);
-		copyNonClassFiles(minecraftProvider.minecraftServerJar, minecraftMergedPatchedSrgJar);
+		if (getExtension().isForgeAndNotOfficial()) {
+			// Copy resources
+			MinecraftProviderImpl minecraftProvider = getExtension().getMinecraftProvider();
+			copyNonClassFiles(minecraftProvider.minecraftClientJar, minecraftMergedPatchedSrgJar);
+			copyNonClassFiles(minecraftProvider.minecraftServerJar, minecraftMergedPatchedSrgJar);
+		}
 	}
 
 	private void walkFileSystems(File source, File target, Predicate<Path> filter, Function<FileSystem, Iterable<Path>> toWalk, FsPathConsumer action)
@@ -576,6 +745,7 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 					FileSystemUtil.FileSystemDelegate targetFs = FileSystemUtil.getJarFileSystem(target, false)) {
 			for (Path sourceDir : toWalk.apply(sourceFs.get())) {
 				Path dir = sourceDir.toAbsolutePath();
+				if (!Files.exists(dir)) continue;
 				Files.walk(dir)
 						.filter(Files::isRegularFile)
 						.filter(filter)
@@ -616,9 +786,12 @@ public class MinecraftPatchedProvider extends DependencyProvider {
 	}
 
 	private void copyNonClassFiles(File source, File target) throws IOException {
-		Predicate<Path> filter = file -> {
+		Predicate<Path> filter = getExtension().isForgeAndOfficial() ? file -> {
 			String s = file.toString();
 			return !s.endsWith(".class");
+		} : file -> {
+			String s = file.toString();
+			return !s.endsWith(".class") || (s.startsWith("META-INF") && !s.startsWith("META-INF/services"));
 		};
 
 		walkFileSystems(source, target, filter, this::copyReplacing);
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/forge/PatchProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/forge/PatchProvider.java
index 2d6d8f46..d49ae8b4 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/forge/PatchProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/forge/PatchProvider.java
@@ -43,7 +43,6 @@ import net.fabricmc.loom.util.Constants;
 public class PatchProvider extends DependencyProvider {
 	public Path clientPatches;
 	public Path serverPatches;
-	public String forgeVersion;
 	public Path projectCacheFolder;
 
 	public PatchProvider(Project project) {
@@ -67,8 +66,7 @@ public class PatchProvider extends DependencyProvider {
 	}
 
 	private void init(String forgeVersion) {
-		this.forgeVersion = forgeVersion;
-		projectCacheFolder = getDirectories().getProjectPersistentCache().toPath().resolve(forgeVersion);
+		projectCacheFolder = getMinecraftProvider().dir("forge/" + forgeVersion).toPath();
 		clientPatches = projectCacheFolder.resolve("patches-client.lzma");
 		serverPatches = projectCacheFolder.resolve("patches-server.lzma");
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/GradleMappingContext.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/GradleMappingContext.java
index 047d75af..e62e9e91 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/GradleMappingContext.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/GradleMappingContext.java
@@ -25,9 +25,7 @@
 package net.fabricmc.loom.configuration.providers.mappings;
 
 import java.io.File;
-import java.io.IOException;
 
-import org.apache.commons.io.FileUtils;
 import org.gradle.api.Project;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.logging.Logger;
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingsDependency.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingsDependency.java
index 878a37e4..ff48a5cf 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingsDependency.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingsDependency.java
@@ -35,8 +35,19 @@ import java.util.Collections;
 import java.util.Objects;
 import java.util.Set;
 
+import org.gradle.api.Action;
 import org.gradle.api.artifacts.Dependency;
+import org.gradle.api.artifacts.ExternalDependency;
+import org.gradle.api.artifacts.ExternalModuleDependency;
+import org.gradle.api.artifacts.ModuleIdentifier;
+import org.gradle.api.artifacts.ModuleVersionIdentifier;
+import org.gradle.api.artifacts.MutableVersionConstraint;
 import org.gradle.api.artifacts.SelfResolvingDependency;
+import org.gradle.api.artifacts.VersionConstraint;
+import org.gradle.api.internal.artifacts.DefaultModuleIdentifier;
+import org.gradle.api.internal.artifacts.ModuleVersionSelectorStrictSpec;
+import org.gradle.api.internal.artifacts.dependencies.AbstractModuleDependency;
+import org.gradle.api.internal.artifacts.dependencies.DefaultMutableVersionConstraint;
 import org.gradle.api.tasks.TaskDependency;
 import org.zeroturnaround.zip.ByteSource;
 import org.zeroturnaround.zip.ZipEntrySource;
@@ -48,7 +59,7 @@ import net.fabricmc.mappingio.adapter.MappingSourceNsSwitch;
 import net.fabricmc.mappingio.format.Tiny2Writer;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 
-public class LayeredMappingsDependency implements SelfResolvingDependency {
+public class LayeredMappingsDependency extends AbstractModuleDependency implements SelfResolvingDependency, ExternalModuleDependency {
 	private static final String GROUP = "loom";
 	private static final String MODULE = "mappings";
 
@@ -57,6 +68,7 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 	private final String version;
 
 	public LayeredMappingsDependency(MappingContext mappingContext, LayeredMappingSpec layeredMappingSpec, String version) {
+		super(null);
 		this.mappingContext = mappingContext;
 		this.layeredMappingSpec = layeredMappingSpec;
 		this.version = version;
@@ -119,6 +131,21 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 	}
 
 	@Override
+	public VersionConstraint getVersionConstraint() {
+		return new DefaultMutableVersionConstraint(getVersion());
+	}
+
+	@Override
+	public boolean matchesStrictly(ModuleVersionIdentifier identifier) {
+		return new ModuleVersionSelectorStrictSpec(this).isSatisfiedBy(identifier);
+	}
+
+	@Override
+	public ModuleIdentifier getModule() {
+		return DefaultModuleIdentifier.newId(GROUP, MODULE);
+	}
+
+	@Override
 	public boolean contentEquals(Dependency dependency) {
 		if (dependency instanceof LayeredMappingsDependency layeredMappingsDependency) {
 			return Objects.equals(layeredMappingsDependency.getVersion(), this.getVersion());
@@ -128,11 +155,35 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 	}
 
 	@Override
-	public Dependency copy() {
+	public boolean isChanging() {
+		return false;
+	}
+
+	@Override
+	public ExternalModuleDependency setChanging(boolean b) {
+		return this;
+	}
+
+	@Override
+	public boolean isForce() {
+		return false;
+	}
+
+	@Override
+	public ExternalDependency setForce(boolean b) {
+		return this;
+	}
+
+	@Override
+	public ExternalModuleDependency copy() {
 		return new LayeredMappingsDependency(mappingContext, layeredMappingSpec, version);
 	}
 
 	@Override
+	public void version(Action<? super MutableVersionConstraint> action) {
+	}
+
+	@Override
 	public String getReason() {
 		return null;
 	}
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
index edddf340..eb6343cc 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingsProviderImpl.java
@@ -27,6 +27,7 @@ package net.fabricmc.loom.configuration.providers.mappings;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.FileSystem;
@@ -151,7 +152,7 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		if (getExtension().shouldGenerateSrgTiny()) {
 			if (Files.notExists(tinyMappingsWithSrg) || isRefreshDeps()) {
 				// Merge tiny mappings with srg
-				SrgMerger.mergeSrg(getExtension().getSrgProvider().getSrg().toPath(), tinyMappings, tinyMappingsWithSrg, true);
+				SrgMerger.mergeSrg(this::getMojmapSrgFileIfPossible, getRawSrgFile(), tinyMappings, tinyMappingsWithSrg, true);
 			}
 		}
 
@@ -216,7 +217,27 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		mappedProvider.provide(dependency, postPopulationScheduler);
 	}
 
-	public void manipulateMappings(Path mappingsJar) throws IOException { }
+	protected Path getRawSrgFile() throws IOException {
+		LoomGradleExtension extension = getExtension();
+
+		if (extension.isForgeAndOfficial()) {
+			return patchedProvider.getMergedMojangTsrg2(false);
+		}
+
+		return extension.getSrgProvider().getSrg().toPath();
+	}
+
+	protected Path getMojmapSrgFileIfPossible() {
+		try {
+			LoomGradleExtension extension = getExtension();
+			return MinecraftPatchedProvider.getMojmapTsrg2(extension);
+		} catch (IOException e) {
+			throw new UncheckedIOException(e);
+		}
+	}
+
+	public void manipulateMappings(Path mappingsJar) throws IOException {
+	}
 
 	private String getMappingsClassifier(DependencyInfo dependency, boolean isV2) {
 		String[] depStringSplit = dependency.getDepString().split(":");
@@ -248,7 +269,8 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		}
 	}
 
-	private void storeMappings(Project project, MinecraftProviderImpl minecraftProvider, Path yarnJar, Consumer<Runnable> postPopulationScheduler) throws IOException {
+	private void storeMappings(Project project, MinecraftProviderImpl minecraftProvider, Path yarnJar, Consumer<Runnable> postPopulationScheduler)
+			throws IOException {
 		project.getLogger().info(":extracting " + yarnJar.getFileName());
 
 		if (isMCP(yarnJar)) {
@@ -298,7 +320,7 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 			provider.provide(DependencyInfo.create(getProject(), configuration.getDependencies().iterator().next(), configuration), postPopulationScheduler);
 		}
 
-		Path srgPath = provider.getSrg().toPath();
+		Path srgPath = getRawSrgFile();
 		TinyFile file = new MCPReader(intermediaryTinyPath, srgPath).read(mcpJar);
 		TinyV2Writer.write(file, tinyMappings);
 	}
@@ -426,20 +448,20 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 		try {
 			Command command = new CommandMergeTinyV2();
 			runCommand(command, intermediaryMappings.toAbsolutePath().toString(),
-							yarnMappings.toAbsolutePath().toString(),
-							newMergedMappings.toAbsolutePath().toString(),
-							"intermediary", "official");
+					yarnMappings.toAbsolutePath().toString(),
+					newMergedMappings.toAbsolutePath().toString(),
+					"intermediary", "official");
 		} catch (Exception e) {
 			throw new RuntimeException("Could not merge mappings from " + intermediaryMappings.toString()
-							+ " with mappings from " + yarnMappings, e);
+			                           + " with mappings from " + yarnMappings, e);
 		}
 	}
 
 	private void suggestFieldNames(MinecraftProviderImpl minecraftProvider, Path oldMappings, Path newMappings) {
 		Command command = new CommandProposeFieldNames();
 		runCommand(command, minecraftProvider.getMergedJar().getAbsolutePath(),
-						oldMappings.toAbsolutePath().toString(),
-						newMappings.toAbsolutePath().toString());
+				oldMappings.toAbsolutePath().toString(),
+				newMappings.toAbsolutePath().toString());
 	}
 
 	private void runCommand(Command command, String... args) {
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
index a396e5b4..1407511e 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftMappedProvider.java
@@ -101,7 +101,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
 			needToRemap = true;
 		}
 
-		if (getExtension().isForge() && (!getForgeMappedJar().exists() || !getForgeIntermediaryJar().exists() || !getForgeSrgJar().exists() || isRefreshDeps() || isForgeAtDirty)) {
+		if (getExtension().isForgeAndNotOfficial() && (!getForgeMappedJar().exists() || !getForgeIntermediaryJar().exists() || !getForgeSrgJar().exists() || isRefreshDeps() || isForgeAtDirty)) {
 			needToRemap = true;
 		}
 
@@ -120,7 +120,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
 				minecraftSrgJar.delete();
 			}
 
-			if (getExtension().isForge()) {
+			if (getExtension().isForgeAndNotOfficial()) {
 				if (getForgeMappedJar().exists()) {
 					getForgeMappedJar().delete();
 				}
@@ -158,16 +158,18 @@ public class MinecraftMappedProvider extends DependencyProvider {
 
 		addDependencies(dependency, postPopulationScheduler);
 
-		if (getExtension().isForge()) {
+		if (getExtension().isForgeAndNotOfficial()) {
 			getProject().getRepositories().flatDir(repository -> repository.dir(new File(getJarDirectory(getDirectories().getUserCache(), "mapped"), "forge")));
 
 			getProject().getDependencies().add(Constants.Configurations.FORGE_NAMED,
-					getProject().getDependencies().module("net.minecraftforge-loom:forge:" + getJarVersionString("mapped")));
+					getProject().getDependencies().module("net.minecraftforge-loom:forge-mapped:" + getMinecraftProvider().minecraftVersion() + "/" + getExtension().getMappingsProvider().mappingsIdentifier() + "/forge"));
+		}
 
+		if (getExtension().isForge()) {
 			getProject().afterEvaluate(project -> {
 				if (!OperatingSystem.isCIBuild()) {
 					try {
-						ForgeSourcesRemapper.addBaseForgeSources(project);
+						ForgeSourcesRemapper.addBaseForgeSources(project, getExtension().isForgeAndOfficial());
 					} catch (IOException e) {
 						e.printStackTrace();
 					}
@@ -241,13 +243,13 @@ public class MinecraftMappedProvider extends DependencyProvider {
 		forgeAssets.toFile().deleteOnExit();
 
 		Info vanilla = new Info(vanillaAssets, input, outputMapped, outputIntermediary, outputSrg);
-		Info forge = getExtension().isForge() ? new Info(forgeAssets, inputForge, forgeOutputMapped, forgeOutputIntermediary, forgeOutputSrg) : null;
+		Info forge = getExtension().isForgeAndNotOfficial() ? new Info(forgeAssets, inputForge, forgeOutputMapped, forgeOutputIntermediary, forgeOutputSrg) : null;
 
 		TinyRemapper remapper = remapperArray[0] = buildRemapper();
 
 		assetsOut(input, vanillaAssets);
 
-		if (getExtension().isForge()) {
+		if (getExtension().isForgeAndNotOfficial()) {
 			assetsOut(inputForge, forgeAssets);
 		}
 
@@ -271,6 +273,8 @@ public class MinecraftMappedProvider extends DependencyProvider {
 	}
 
 	public void remap(TinyRemapper remapper, Info vanilla, @Nullable Info forge, String fromM) throws IOException {
+		Set<String> classNames = getExtension().isForge() ? InnerClassRemapper.readClassNames(vanilla.input) : null;
+
 		for (String toM : getExtension().isForge() ? Arrays.asList("intermediary", "srg", "named") : Arrays.asList("intermediary", "named")) {
 			Path output = "named".equals(toM) ? vanilla.outputMapped : "srg".equals(toM) ? vanilla.outputSrg : vanilla.outputIntermediary;
 			Path outputForge = forge == null ? null : "named".equals(toM) ? forge.outputMapped : "srg".equals(toM) ? forge.outputSrg : forge.outputIntermediary;
@@ -285,7 +289,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
 				remapper.readInputs(forgeTag, forge.input);
 			}
 
-			remapper.replaceMappings(getMappings(vanilla.input, fromM, toM));
+			remapper.replaceMappings(getMappings(classNames, fromM, toM));
 			OutputRemappingHandler.remap(remapper, vanilla.assets, output, null, vanillaTag);
 
 			if (forge != null) {
@@ -325,13 +329,13 @@ public class MinecraftMappedProvider extends DependencyProvider {
 		return builder.build();
 	}
 
-	public Set<IMappingProvider> getMappings(@Nullable Path fromJar, String fromM, String toM) throws IOException {
+	public Set<IMappingProvider> getMappings(@Nullable Set<String> fromClassNames, String fromM, String toM) throws IOException {
 		Set<IMappingProvider> providers = new HashSet<>();
 		providers.add(TinyRemapperMappingsHelper.create(getExtension().isForge() ? getExtension().getMappingsProvider().getMappingsWithSrg() : getExtension().getMappingsProvider().getMappings(), fromM, toM, true));
 
 		if (getExtension().isForge()) {
-			if (fromJar != null) {
-				providers.add(InnerClassRemapper.of(fromJar, getExtension().getMappingsProvider().getMappingsWithSrg(), fromM, toM));
+			if (fromClassNames != null) {
+				providers.add(InnerClassRemapper.of(fromClassNames, getExtension().getMappingsProvider().getMappingsWithSrg(), fromM, toM));
 			}
 		} else {
 			providers.add(out -> JSR_TO_JETBRAINS.forEach(out::acceptClass));
@@ -357,11 +361,16 @@ public class MinecraftMappedProvider extends DependencyProvider {
 		minecraftMappedJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "minecraft-mapped.jar");
 		inputJar = getExtension().isForge() ? mappingsProvider.patchedProvider.getMergedJar() : minecraftProvider.getMergedJar();
 
-		if (getExtension().isForge()) {
+		if (getExtension().isForgeAndNotOfficial()) {
 			inputForgeJar = mappingsProvider.patchedProvider.getForgeMergedJar();
-			forgeIntermediaryJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "forge-intermediary.jar");
-			forgeSrgJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "forge-srg.jar");
+			forgeIntermediaryJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "forge/forge-intermediary.jar");
+			forgeSrgJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "forge/forge-srg.jar");
 			forgeMappedJar = new File(getExtension().getMappingsProvider().mappingsWorkingDir().toFile(), "forge/forge-mapped.jar");
+		} else {
+			inputForgeJar = null;
+			forgeIntermediaryJar = null;
+			forgeSrgJar = null;
+			forgeMappedJar = null;
 		}
 	}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/sources/ForgeSourcesRemapper.java b/src/main/java/net/fabricmc/loom/configuration/sources/ForgeSourcesRemapper.java
index db56ae5e..0e204eb4 100644
--- a/src/main/java/net/fabricmc/loom/configuration/sources/ForgeSourcesRemapper.java
+++ b/src/main/java/net/fabricmc/loom/configuration/sources/ForgeSourcesRemapper.java
@@ -58,8 +58,8 @@ import net.fabricmc.loom.util.ThreadingUtils;
 import net.fabricmc.lorenztiny.TinyMappingsReader;
 
 public class ForgeSourcesRemapper {
-	public static void addBaseForgeSources(Project project) throws IOException {
-		Path sourcesJar = GenerateSourcesTask.getMappedJarFileWithSuffix(project, "-sources.jar", true).toPath();
+	public static void addBaseForgeSources(Project project, boolean isOfficial) throws IOException {
+		Path sourcesJar = GenerateSourcesTask.getMappedJarFileWithSuffix(project, "-sources.jar", !isOfficial).toPath();
 
 		if (!Files.exists(sourcesJar)) {
 			addForgeSources(project, sourcesJar);
@@ -185,7 +185,11 @@ public class ForgeSourcesRemapper {
 
 		// Distinct and add the srg jar at the top, so it gets prioritized
 		mercury.getClassPath().add(0, extension.getMinecraftMappedProvider().getSrgJar().toPath());
-		mercury.getClassPath().add(0, extension.getMinecraftMappedProvider().getForgeSrgJar().toPath());
+
+		if (extension.isForgeAndNotOfficial()) {
+			mercury.getClassPath().add(0, extension.getMinecraftMappedProvider().getForgeSrgJar().toPath());
+		}
+
 		List<Path> newClassPath = mercury.getClassPath().stream()
 				.distinct()
 				.filter(Files::isRegularFile)
diff --git a/src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java b/src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java
index 5feeafbe..1f274f12 100644
--- a/src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java
+++ b/src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java
@@ -367,6 +367,16 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 		}
 
 		@Override
+		public boolean isForgeAndOfficial() {
+			throw new RuntimeException("Yeah... something is really wrong");
+		}
+
+		@Override
+		public boolean isForgeAndNotOfficial() {
+			throw new RuntimeException("Yeah... something is really wrong");
+		}
+
+		@Override
 		protected String getMinecraftVersion() {
 			throw new RuntimeException("Yeah... something is really wrong");
 		}
diff --git a/src/main/java/net/fabricmc/loom/extension/MinecraftGradleExtension.java b/src/main/java/net/fabricmc/loom/extension/MinecraftGradleExtension.java
index 2921b451..5550cb8a 100644
--- a/src/main/java/net/fabricmc/loom/extension/MinecraftGradleExtension.java
+++ b/src/main/java/net/fabricmc/loom/extension/MinecraftGradleExtension.java
@@ -161,6 +161,18 @@ public class MinecraftGradleExtension implements LoomGradleExtensionAPI {
 	}
 
 	@Override
+	public boolean isForgeAndOfficial() {
+		reportDeprecation();
+		return parent.isForgeAndOfficial();
+	}
+
+	@Override
+	public boolean isForgeAndNotOfficial() {
+		reportDeprecation();
+		return parent.isForgeAndNotOfficial();
+	}
+
+	@Override
 	public boolean supportsInclude() {
 		reportDeprecation();
 		return parent.supportsInclude();
diff --git a/src/main/java/net/fabricmc/loom/task/LoomTasks.java b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
index 883169f8..5f41b03e 100644
--- a/src/main/java/net/fabricmc/loom/task/LoomTasks.java
+++ b/src/main/java/net/fabricmc/loom/task/LoomTasks.java
@@ -25,6 +25,8 @@
 package net.fabricmc.loom.task;
 
 import java.io.File;
+import java.io.IOException;
+import java.io.UncheckedIOException;
 
 import com.google.common.base.Preconditions;
 import org.gradle.api.Project;
@@ -33,6 +35,7 @@ import org.gradle.api.tasks.TaskContainer;
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.api.decompilers.LoomDecompiler;
 import net.fabricmc.loom.configuration.ide.RunConfigSettings;
+import net.fabricmc.loom.configuration.ide.SetupIntelijRunConfigs;
 import net.fabricmc.loom.configuration.providers.mappings.MappingsProviderImpl;
 import net.fabricmc.loom.decompilers.fernflower.FabricFernFlowerDecompiler;
 import net.fabricmc.loom.util.Constants;
@@ -86,6 +89,19 @@ public final class LoomTasks {
 			t.dependsOn("downloadAssets");
 			t.setGroup(Constants.TaskGroup.IDE);
 		});
+
+		tasks.register("genIntelliJRuns", AbstractLoomTask.class, t -> {
+			t.setDescription("Generates IntelliJ IDEA launch configurations.");
+			t.dependsOn("downloadAssets");
+			t.setGroup("ide");
+			t.doLast(task -> {
+				try {
+					SetupIntelijRunConfigs.generate(task.getProject(), true);
+				} catch (IOException e) {
+					throw new UncheckedIOException(e);
+				}
+			});
+		});
 	}
 
 	private static void registerRunTasks(TaskContainer tasks, Project project) {
diff --git a/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java b/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
index 6febed33..84cee1c9 100644
--- a/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
+++ b/src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java
@@ -187,9 +187,12 @@ public class MigrateMappingsTask extends AbstractLoomTask {
 
 		if (extension.isForge()) {
 			mercury.getClassPath().add(minecraftMappedProvider.getSrgJar().toPath());
-			mercury.getClassPath().add(minecraftMappedProvider.getForgeMappedJar().toPath());
-			mercury.getClassPath().add(minecraftMappedProvider.getForgeIntermediaryJar().toPath());
-			mercury.getClassPath().add(minecraftMappedProvider.getForgeSrgJar().toPath());
+
+			if (extension.isForgeAndNotOfficial()) {
+				mercury.getClassPath().add(minecraftMappedProvider.getForgeMappedJar().toPath());
+				mercury.getClassPath().add(minecraftMappedProvider.getForgeIntermediaryJar().toPath());
+				mercury.getClassPath().add(minecraftMappedProvider.getForgeSrgJar().toPath());
+			}
 		}
 
 		mercury.getProcessors().add(MercuryRemapper.create(mappingSet));
diff --git a/src/main/java/net/fabricmc/loom/util/Constants.java b/src/main/java/net/fabricmc/loom/util/Constants.java
index f53dbf50..f3f0bf5a 100644
--- a/src/main/java/net/fabricmc/loom/util/Constants.java
+++ b/src/main/java/net/fabricmc/loom/util/Constants.java
@@ -79,6 +79,7 @@ public class Constants {
 		public static final String FORGE_UNIVERSAL = "forgeUniversal";
 		public static final String FORGE_DEPENDENCIES = "forgeDependencies";
 		public static final String FORGE_NAMED = "forgeNamed";
+		public static final String FORGE_EXTRA = "forgeExtra";
 		public static final String MAPPING_CONSTANTS = "mappingsConstants";
 		public static final String UNPICK_CLASSPATH = "unpick";
 
@@ -95,9 +96,10 @@ public class Constants {
 		public static final String TERMINAL_CONSOLE_APPENDER = "net.minecrell:terminalconsoleappender:";
 		public static final String JETBRAINS_ANNOTATIONS = "org.jetbrains:annotations:";
 		public static final String JAVAX_ANNOTATIONS = "com.google.code.findbugs:jsr305:"; // I hate that I have to add these.
-		public static final String FORGE_RUNTIME = "dev.architectury:architectury-loom-forge-runtime:";
+		public static final String FORGE_RUNTIME = "dev.architectury:architectury-loom-runtime:";
 		public static final String ACCESS_TRANSFORMERS = "net.minecraftforge:accesstransformers:";
 		public static final String SPECIAL_SOURCE = "net.md-5:SpecialSource:";
+		public static final String VIGNETTE = "net.minecraftforge.lex:vignette:";
 
 		private Dependencies() {
 		}
@@ -111,9 +113,10 @@ public class Constants {
 			public static final String TERMINAL_CONSOLE_APPENDER = "1.2.0";
 			public static final String JETBRAINS_ANNOTATIONS = "19.0.0";
 			public static final String JAVAX_ANNOTATIONS = "3.0.2";
-			public static final String FORGE_RUNTIME = "$LOOM_VERSION"; // replaced with current version at build time
-			public static final String ACCESS_TRANSFORMERS = "2.2.0";
+			public static final String FORGE_RUNTIME = "1.0.1";
+			public static final String ACCESS_TRANSFORMERS = "3.0.1";
 			public static final String SPECIAL_SOURCE = "1.8.3";
+			public static final String VIGNETTE = "0.2.0.10";
 
 			private Versions() {
 			}
diff --git a/src/main/java/net/fabricmc/loom/util/DependencyDownloader.java b/src/main/java/net/fabricmc/loom/util/DependencyDownloader.java
index a7201cbb..85bcbe00 100644
--- a/src/main/java/net/fabricmc/loom/util/DependencyDownloader.java
+++ b/src/main/java/net/fabricmc/loom/util/DependencyDownloader.java
@@ -24,7 +24,14 @@
 
 package net.fabricmc.loom.util;
 
+import java.io.File;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
 import org.gradle.api.Project;
+import org.gradle.api.artifacts.Configuration;
+import org.gradle.api.artifacts.Dependency;
+import org.gradle.api.artifacts.ModuleDependency;
 import org.gradle.api.file.FileCollection;
 
 /**
@@ -41,8 +48,40 @@ public final class DependencyDownloader {
 	 * @return the resolved files
 	 */
 	public static FileCollection download(Project project, String dependencyNotation) {
-		var dependency = project.getDependencies().create(dependencyNotation);
-		var config = project.getConfigurations().detachedConfiguration(dependency);
-		return config.fileCollection(dep -> true);
+		return download(project, dependencyNotation, true, false);
+	}
+
+	public static FileCollection download(Project project, String dependencyNotation, boolean transitive, boolean resolve) {
+		Dependency dependency = project.getDependencies().create(dependencyNotation);
+
+		if (dependency instanceof ModuleDependency) {
+			((ModuleDependency) dependency).setTransitive(transitive);
+		}
+
+		Configuration config = project.getConfigurations().detachedConfiguration(dependency);
+		config.setTransitive(transitive);
+		FileCollection files = config.fileCollection(dep -> true);
+
+		if (resolve) {
+			files = project.files(files.getFiles());
+		}
+
+		return files;
+	}
+
+	private static Set<File> resolve(Configuration configuration, boolean transitive) {
+		Configuration copy = configuration.copy();
+		copy.setTransitive(transitive);
+		Set<File> files = new LinkedHashSet<>(copy.resolve());
+
+		for (Configuration extendsForm : configuration.getExtendsFrom()) {
+			files.addAll(resolve(extendsForm, transitive));
+		}
+
+		return files;
+	}
+
+	public static Set<File> resolveFiles(Configuration configuration, boolean transitive) {
+		return resolve(configuration, transitive);
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/util/MappingsProviderVerbose.java b/src/main/java/net/fabricmc/loom/util/MappingsProviderVerbose.java
new file mode 100644
index 00000000..6bdb7932
--- /dev/null
+++ b/src/main/java/net/fabricmc/loom/util/MappingsProviderVerbose.java
@@ -0,0 +1,71 @@
+package net.fabricmc.loom.util;
+
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Set;
+
+import dev.architectury.mappingslayers.api.mutable.MutableTinyMetadata;
+import dev.architectury.mappingslayers.api.mutable.MutableTinyTree;
+import dev.architectury.mappingslayers.api.utils.MappingsUtils;
+import dev.architectury.tinyremapper.IMappingProvider;
+import dev.architectury.tinyremapper.TinyRemapper;
+
+public class MappingsProviderVerbose {
+	public static void saveFile(TinyRemapper providers) throws IOException {
+		try {
+			Field field = TinyRemapper.class.getDeclaredField("mappingProviders");
+			field.setAccessible(true);
+			Set<IMappingProvider> mappingProviders = (Set<IMappingProvider>) field.get(providers);
+			saveFile(mappingProviders);
+		} catch (IllegalAccessException | NoSuchFieldException e) {
+			e.printStackTrace();
+		}
+	}
+
+	public static void saveFile(Iterable<IMappingProvider> providers) throws IOException {
+		MutableTinyTree tree = MappingsUtils.create(MutableTinyMetadata.create(2, 0, Arrays.asList("from", "to"), new HashMap<>()));
+
+		for (IMappingProvider provider : providers) {
+			provider.load(new IMappingProvider.MappingAcceptor() {
+				@Override
+				public void acceptClass(String from, String to) {
+					tree.getOrCreateClass(from).setName(1, to);
+				}
+
+				@Override
+				public void acceptMethod(IMappingProvider.Member from, String to) {
+					tree.getOrCreateClass(from.owner).getOrCreateMethod(from.name, from.desc)
+							.setName(1, to);
+				}
+
+				@Override
+				public void acceptMethodArg(IMappingProvider.Member from, int lvIndex, String to) {
+					tree.getOrCreateClass(from.owner).getOrCreateMethod(from.name, from.desc)
+							.getOrCreateParameter(lvIndex, "")
+							.setName(1, to);
+				}
+
+				@Override
+				public void acceptMethodVar(IMappingProvider.Member from, int i, int i1, int i2, String s) {
+					// NO-OP
+				}
+
+				@Override
+				public void acceptField(IMappingProvider.Member from, String to) {
+					tree.getOrCreateClass(from.owner).getOrCreateField(from.name, from.desc)
+							.setName(1, to);
+				}
+			});
+		}
+
+		Path check = Files.createTempFile("CHECK", null);
+		Files.writeString(check, MappingsUtils.serializeToString(tree), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+		System.out.println("Saved debug check mappings to " + check);
+	}
+}
diff --git a/src/main/java/net/fabricmc/loom/util/srg/InnerClassRemapper.java b/src/main/java/net/fabricmc/loom/util/srg/InnerClassRemapper.java
index 1949c55d..edc7e263 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/InnerClassRemapper.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/InnerClassRemapper.java
@@ -27,11 +27,14 @@ package net.fabricmc.loom.util.srg;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.HashSet;
 import java.util.Iterator;
-import java.util.Map;
+import java.util.Set;
 import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
 
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
 import dev.architectury.tinyremapper.IMappingProvider;
 
 import net.fabricmc.loom.util.FileSystemUtil;
@@ -40,22 +43,16 @@ import net.fabricmc.mapping.tree.ClassDef;
 import net.fabricmc.mapping.tree.TinyTree;
 
 public class InnerClassRemapper {
-	public static IMappingProvider of(Path fromJar, TinyTree mappingsWithSrg, String from, String to) throws IOException {
+	public static IMappingProvider of(Set<String> fromClassNames, TinyTree mappingsWithSrg, String from, String to) throws IOException {
 		return sink -> {
-			remapInnerClass(fromJar, mappingsWithSrg, from, to, sink::acceptClass);
+			remapInnerClass(fromClassNames, mappingsWithSrg, from, to, sink::acceptClass);
 		};
 	}
 
-	private static void remapInnerClass(Path fromJar, TinyTree mappingsWithSrg, String from, String to, BiConsumer<String, String> action) {
-		try (FileSystemDelegate system = FileSystemUtil.getJarFileSystem(fromJar, false)) {
-			Map<String, String> availableClasses = mappingsWithSrg.getClasses().stream()
-					.collect(Collectors.groupingBy(classDef -> classDef.getName(from),
-							Collectors.<ClassDef, String>reducing(
-									null,
-									classDef -> classDef.getName(to),
-									(first, last) -> last
-							))
-					);
+	public static Set<String> readClassNames(Path jar) {
+		Set<String> set = new HashSet<>();
+
+		try (FileSystemDelegate system = FileSystemUtil.getJarFileSystem(jar, false)) {
 			Iterator<Path> iterator = Files.walk(system.get().getPath("/")).iterator();
 
 			while (iterator.hasNext()) {
@@ -65,21 +62,42 @@ public class InnerClassRemapper {
 
 				if (!Files.isDirectory(path) && name.contains("$") && name.endsWith(".class")) {
 					String className = name.substring(0, name.length() - 6);
+					set.add(className);
+				}
+			}
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
 
-					if (!availableClasses.containsKey(className)) {
-						String parentName = className.substring(0, className.indexOf('$'));
-						String childName = className.substring(className.indexOf('$') + 1);
-						String remappedParentName = availableClasses.getOrDefault(parentName, parentName);
-						String remappedName = remappedParentName + "$" + childName;
+		return set;
+	}
+
+	private static void remapInnerClass(Set<String> classNames, TinyTree mappingsWithSrg, String from, String to, BiConsumer<String, String> action) {
+		BiMap<String, String> availableClasses = HashBiMap.create(mappingsWithSrg.getClasses().stream()
+				.collect(Collectors.groupingBy(classDef -> classDef.getName(from),
+						Collectors.<ClassDef, String>reducing(
+								null,
+								classDef -> classDef.getName(to),
+								(first, last) -> last
+						))
+				));
+
+		for (String className : classNames) {
+			if (!availableClasses.containsKey(className)) {
+				String parentName = className.substring(0, className.indexOf('$'));
+				String childName = className.substring(className.indexOf('$') + 1);
+				String remappedParentName = availableClasses.getOrDefault(parentName, parentName);
+				String remappedName = remappedParentName + "$" + childName;
 
-						if (!className.equals(remappedName)) {
-							action.accept(className, remappedName);
-						}
+				if (!className.equals(remappedName)) {
+					if (availableClasses.containsValue(remappedName)) {
+						// https://github.com/MinecraftForge/MinecraftForge/blob/b027a92dd287d6810a9fdae4d4b1e1432d7dc9cc/patches/minecraft/net/minecraft/Util.java.patch#L8
+						action.accept(className, remappedName + "_UNBREAK");
+					} else {
+						action.accept(className, remappedName);
 					}
 				}
 			}
-		} catch (IOException e) {
-			throw new RuntimeException(e);
 		}
 	}
 }
diff --git a/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java b/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
index 8d5e7738..327825d3 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/SpecialSourceExecutor.java
@@ -39,6 +39,7 @@ import org.apache.commons.io.output.NullOutputStream;
 import org.gradle.api.Project;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.logging.LogLevel;
+import org.gradle.api.logging.configuration.ShowStacktrace;
 import org.zeroturnaround.zip.ZipUtil;
 
 import net.fabricmc.loom.LoomGradleExtension;
@@ -87,8 +88,10 @@ public class SpecialSourceExecutor {
 			spec.setMain("net.md_5.specialsource.SpecialSource");
 
 			// if running with INFO or DEBUG logging
-			if (project.getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) < 0) {
+			if (project.getGradle().getStartParameter().getShowStacktrace() != ShowStacktrace.INTERNAL_EXCEPTIONS
+						|| project.getGradle().getStartParameter().getLogLevel().compareTo(LogLevel.LIFECYCLE) < 0) {
 				spec.setStandardOutput(System.out);
+				spec.setErrorOutput(System.err);
 			} else {
 				spec.setStandardOutput(NullOutputStream.NULL_OUTPUT_STREAM);
 				spec.setErrorOutput(NullOutputStream.NULL_OUTPUT_STREAM);
diff --git a/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java b/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
index 39a2b57c..e2cf730f 100644
--- a/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
+++ b/src/main/java/net/fabricmc/loom/util/srg/SrgMerger.java
@@ -27,15 +27,20 @@ package net.fabricmc.loom.util.srg;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.StringReader;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
+import com.google.common.base.MoreObjects;
 import dev.architectury.mappingslayers.api.mutable.MutableClassDef;
+import dev.architectury.mappingslayers.api.mutable.MutableDescriptored;
 import dev.architectury.mappingslayers.api.mutable.MutableFieldDef;
 import dev.architectury.mappingslayers.api.mutable.MutableMethodDef;
 import dev.architectury.mappingslayers.api.mutable.MutableTinyTree;
@@ -56,6 +61,7 @@ import net.fabricmc.mapping.tree.FieldDef;
 import net.fabricmc.mapping.tree.MethodDef;
 import net.fabricmc.mapping.tree.TinyMappingFactory;
 import net.fabricmc.mapping.tree.TinyTree;
+import net.fabricmc.mappingio.format.TsrgReader;
 import net.fabricmc.stitch.commands.tinyv2.TinyClass;
 import net.fabricmc.stitch.commands.tinyv2.TinyField;
 import net.fabricmc.stitch.commands.tinyv2.TinyFile;
@@ -80,8 +86,9 @@ public final class SrgMerger {
 	 * @throws MappingException if the input tiny tree's default namespace is not 'official'
 	 *                          or if an element mentioned in the SRG file does not have tiny mappings
 	 */
-	public static void mergeSrg(Path srg, Path tiny, Path out, boolean lenient) throws IOException, MappingException {
-		MappingSet arr = readSrg(srg);
+	public static void mergeSrg(Supplier<Path> mojmap, Path srg, Path tiny, Path out, boolean lenient) throws IOException, MappingException {
+		Map<String, List<MutableDescriptored>> addRegardlessSrgs = new HashMap<>();
+		MappingSet arr = readSrg(srg, mojmap, addRegardlessSrgs);
 		TinyTree foss;
 
 		try (BufferedReader reader = Files.newBufferedReader(tiny)) {
@@ -100,19 +107,19 @@ public final class SrgMerger {
 		List<TinyClass> classes = new ArrayList<>();
 
 		for (TopLevelClassMapping klass : arr.getTopLevelClassMappings()) {
-			classToTiny(foss, namespaces, klass, classes::add, lenient);
+			classToTiny(addRegardlessSrgs, foss, namespaces, klass, classes::add, lenient);
 		}
 
 		TinyFile file = new TinyFile(header, classes);
 		TinyV2Writer.write(file, out);
 	}
 
-	private static MappingSet readSrg(Path srg) throws IOException {
+	private static MappingSet readSrg(Path srg, Supplier<Path> mojmap, Map<String, List<MutableDescriptored>> addRegardlessSrgs) throws IOException {
 		try (BufferedReader reader = Files.newBufferedReader(srg)) {
 			String content = IOUtils.toString(reader);
 
 			if (content.startsWith("tsrg2")) {
-				return readTsrg2(content);
+				return readTsrg2(content, mojmap, addRegardlessSrgs);
 			} else {
 				try (TSrgReader srgReader = new TSrgReader(new StringReader(content))) {
 					return srgReader.read();
@@ -121,31 +128,45 @@ public final class SrgMerger {
 		}
 	}
 
-	private static MappingSet readTsrg2(String content) {
-		MappingSet set = MappingSet.create();
-		MutableTinyTree tree = MappingsUtils.deserializeFromTsrg2(content);
-		int obfIndex = tree.getMetadata().index("obf");
-		int srgIndex = tree.getMetadata().index("srg");
+	private static MappingSet readTsrg2(String content, Supplier<Path> mojmap, Map<String, List<MutableDescriptored>> addRegardlessSrgs) throws IOException {
+		MappingSet set;
 
-		for (MutableClassDef classDef : tree.getClassesMutable()) {
-			ClassMapping<?, ?> classMapping = set.getOrCreateClassMapping(classDef.getName(obfIndex));
-			classMapping.setDeobfuscatedName(classDef.getName(srgIndex));
+		try (Tsrg2Utils.MappingsIO2LorenzWriter lorenzWriter = new Tsrg2Utils.MappingsIO2LorenzWriter(0, false)) {
+			TsrgReader.read(new StringReader(content), lorenzWriter);
+			set = lorenzWriter.read();
+			MutableTinyTree mojmapTree = readTsrg2ToTinyTree(mojmap.get());
 
-			for (MutableFieldDef fieldDef : classDef.getFieldsMutable()) {
-				FieldMapping fieldMapping = classMapping.getOrCreateFieldMapping(fieldDef.getName(obfIndex));
-				fieldMapping.setDeobfuscatedName(fieldDef.getName(srgIndex));
-			}
+			for (MutableClassDef classDef : mojmapTree.getClassesMutable()) {
+				for (MutableMethodDef methodDef : classDef.getMethodsMutable()) {
+					String name = methodDef.getName(0);
+
+					if (name.indexOf('<') != 0 && name.equals(methodDef.getName(1))) {
+						addRegardlessSrgs.computeIfAbsent(classDef.getName(0), $ -> new ArrayList<>()).add(methodDef);
+					}
+				}
 
-			for (MutableMethodDef methodDef : classDef.getMethodsMutable()) {
-				MethodMapping methodMapping = classMapping.getOrCreateMethodMapping(methodDef.getName(obfIndex), methodDef.getDescriptor(obfIndex));
-				methodMapping.setDeobfuscatedName(methodDef.getName(srgIndex));
+				for (MutableFieldDef fieldDef : classDef.getFieldsMutable()) {
+					if (fieldDef.getName(0).equals(fieldDef.getName(1))) {
+						addRegardlessSrgs.computeIfAbsent(classDef.getName(0), $ -> new ArrayList<>()).add(fieldDef);
+					}
+				}
 			}
 		}
 
 		return set;
 	}
 
-	private static void classToTiny(TinyTree foss, List<String> namespaces, ClassMapping<?, ?> klass, Consumer<TinyClass> classConsumer, boolean lenient) {
+	private static MutableTinyTree readTsrg2ToTinyTree(Path path) throws IOException {
+		MutableTinyTree tree;
+
+		try (BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
+			tree = MappingsUtils.deserializeFromTsrg2(IOUtils.toString(reader));
+		}
+
+		return tree;
+	}
+
+	private static void classToTiny(Map<String, List<MutableDescriptored>> addRegardlessSrgs, TinyTree foss, List<String> namespaces, ClassMapping<?, ?> klass, Consumer<TinyClass> classConsumer, boolean lenient) {
 		String obf = klass.getFullObfuscatedName();
 		String srg = klass.getFullDeobfuscatedName();
 		ClassDef classDef = foss.getDefaultNamespaceClassMap().get(obf);
@@ -170,9 +191,17 @@ public final class SrgMerger {
 			MethodDef def = CollectionUtil.find(
 					classDef.getMethods(),
 					m -> m.getName("official").equals(method.getObfuscatedName()) && m.getDescriptor("official").equals(method.getObfuscatedDescriptor())
-			).orElse(nullOrThrow(lenient, () -> new MappingException("Missing method: " + method.getFullObfuscatedName() + " (srg: " + method.getFullDeobfuscatedName() + ")")));
+			).orElse(null);
 
-			if (def == null) continue;
+			if (def == null) {
+				if (tryMatchRegardlessSrgs(addRegardlessSrgs, namespaces, obf, methods, method)) continue;
+
+				if (!lenient) {
+					throw new MappingException("Missing method: " + method.getFullObfuscatedName() + " (srg: " + method.getFullDeobfuscatedName() + ")");
+				}
+
+				continue;
+			}
 
 			List<String> methodNames = CollectionUtil.map(
 					namespaces,
@@ -207,8 +236,34 @@ public final class SrgMerger {
 		classConsumer.accept(tinyClass);
 
 		for (InnerClassMapping innerKlass : klass.getInnerClassMappings()) {
-			classToTiny(foss, namespaces, innerKlass, classConsumer, lenient);
+			classToTiny(addRegardlessSrgs, foss, namespaces, innerKlass, classConsumer, lenient);
+		}
+	}
+
+	private static boolean tryMatchRegardlessSrgs(Map<String, List<MutableDescriptored>> addRegardlessSrgs, List<String> namespaces, String obf,
+			List<TinyMethod> methods, MethodMapping method) {
+		List<MutableDescriptored> mutableDescriptoredList = addRegardlessSrgs.get(obf);
+
+		if (!method.getDeobfuscatedName().equals(method.getObfuscatedName())) {
+			for (MutableDescriptored descriptored : MoreObjects.firstNonNull(mutableDescriptoredList, Collections.<MutableDescriptored>emptyList())) {
+				if (descriptored.isMethod() && descriptored.getName(0).equals(method.getObfuscatedName()) && descriptored.getDescriptor(0).equals(method.getObfuscatedDescriptor())) {
+					List<String> methodNames = CollectionUtil.map(
+							namespaces,
+							namespace -> "srg".equals(namespace) ? method.getDeobfuscatedName() : method.getObfuscatedName()
+					);
+
+					methods.add(new TinyMethod(
+							method.getObfuscatedDescriptor(), methodNames,
+							/* parameters */ Collections.emptyList(),
+							/* locals */ Collections.emptyList(),
+							/* comments */ Collections.emptyList()
+					));
+					return true;
+				}
+			}
 		}
+
+		return false;
 	}
 
 	@Nullable
diff --git a/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Utils.java b/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Utils.java
new file mode 100644
index 00000000..e6ddf578
--- /dev/null
+++ b/src/main/java/net/fabricmc/loom/util/srg/Tsrg2Utils.java
@@ -0,0 +1,209 @@
+package net.fabricmc.loom.util.srg;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.UncheckedIOException;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+
+import dev.architectury.mappingslayers.api.mutable.MutableClassDef;
+import dev.architectury.mappingslayers.api.mutable.MutableFieldDef;
+import dev.architectury.mappingslayers.api.mutable.MutableMethodDef;
+import dev.architectury.mappingslayers.api.mutable.MutableParameterDef;
+import dev.architectury.mappingslayers.api.mutable.MutableTinyMetadata;
+import dev.architectury.mappingslayers.api.mutable.MutableTinyTree;
+import dev.architectury.mappingslayers.api.utils.MappingsUtils;
+import org.cadixdev.lorenz.MappingSet;
+import org.cadixdev.lorenz.io.srg.tsrg.TSrgWriter;
+import org.cadixdev.lorenz.model.ClassMapping;
+import org.cadixdev.lorenz.model.MethodMapping;
+
+import net.fabricmc.mappingio.MappingVisitor;
+import net.fabricmc.mappingio.MappingWriter;
+import net.fabricmc.mappingio.adapter.ForwardingMappingVisitor;
+import net.fabricmc.mappingio.format.TsrgReader;
+import net.fabricmc.mappingio.tree.MappingTree;
+import net.fabricmc.mappingio.tree.MemoryMappingTree;
+
+public class Tsrg2Utils {
+	public static void convert(Reader reader, Writer writer) throws IOException {
+		writeTsrg(visitor -> {
+			try {
+				TsrgReader.read(reader, visitor);
+			} catch (IOException e) {
+				throw new UncheckedIOException(e);
+			}
+		}, "srg", false, writer);
+	}
+
+	public static void writeTsrg(Consumer<MappingVisitor> visitorConsumer, String dstNamespace, boolean applyParameterMappings, Writer writer)
+			throws IOException {
+		MappingSet set;
+
+		try (MappingsIO2LorenzWriter lorenzWriter = new MappingsIO2LorenzWriter(dstNamespace, applyParameterMappings)) {
+			visitorConsumer.accept(lorenzWriter);
+			set = lorenzWriter.read();
+		}
+
+		try (TSrgWriter w = new TSrgWriter(writer)) {
+			w.write(set);
+		}
+	}
+
+	public static void writeTsrg2(Consumer<MappingVisitor> visitorConsumer, Writer writer)
+			throws IOException {
+		MutableTinyTree tree;
+
+		try (MappingsIO2MappingsUtils w = new MappingsIO2MappingsUtils()) {
+			visitorConsumer.accept(w);
+			tree = w.read();
+		}
+
+		writer.write(MappingsUtils.serializeToTsrg2(tree));
+	}
+
+	// TODO Move this elsewhere
+	public abstract static class MappingsIO2Others extends ForwardingMappingVisitor implements MappingWriter {
+		public MappingsIO2Others() {
+			super(new MemoryMappingTree());
+		}
+
+		public MappingTree tree() {
+			return (MappingTree) next;
+		}
+
+		@Override
+		public void close() throws IOException {
+			MappingTree tree = tree();
+			List<String> names = new ArrayList<>();
+
+			for (MappingTree.ClassMapping aClass : tree.getClasses()) {
+				names.add(aClass.getSrcName());
+			}
+
+			for (String name : names) {
+				tree.removeClass(name);
+			}
+		}
+	}
+
+	public static class MappingsIO2LorenzWriter extends MappingsIO2Others {
+		private final Object dstNamespaceUnresolved;
+		private int dstNamespace;
+		private boolean applyParameterMappings;
+
+		public MappingsIO2LorenzWriter(int dstNamespace, boolean applyParameterMappings) {
+			this.dstNamespaceUnresolved = dstNamespace;
+			this.applyParameterMappings = applyParameterMappings;
+		}
+
+		public MappingsIO2LorenzWriter(String dstNamespace, boolean applyParameterMappings) {
+			this.dstNamespaceUnresolved = dstNamespace;
+			this.applyParameterMappings = applyParameterMappings;
+		}
+
+		@Override
+		public void visitNamespaces(String srcNamespace, List<String> dstNamespaces) throws IOException {
+			super.visitNamespaces(srcNamespace, dstNamespaces);
+			this.dstNamespace = dstNamespaceUnresolved instanceof Integer ? (Integer) dstNamespaceUnresolved : dstNamespaces.indexOf((String) dstNamespaceUnresolved);
+		}
+
+		public MappingSet read() throws IOException {
+			return this.read(MappingSet.create());
+		}
+
+		public MappingSet read(final MappingSet mappings) throws IOException {
+			MappingTree tree = tree();
+
+			for (MappingTree.ClassMapping aClass : tree.getClasses()) {
+				ClassMapping<?, ?> lClass = mappings.getOrCreateClassMapping(aClass.getSrcName())
+						.setDeobfuscatedName(aClass.getDstName(dstNamespace));
+
+				for (MappingTree.FieldMapping aField : aClass.getFields()) {
+					String srcDesc = aField.getSrcDesc();
+
+					if (srcDesc == null || srcDesc.isEmpty()) {
+						lClass.getOrCreateFieldMapping(aField.getSrcName())
+								.setDeobfuscatedName(aField.getDstName(dstNamespace));
+					} else {
+						lClass.getOrCreateFieldMapping(aField.getSrcName(), srcDesc)
+								.setDeobfuscatedName(aField.getDstName(dstNamespace));
+					}
+				}
+
+				for (MappingTree.MethodMapping aMethod : aClass.getMethods()) {
+					MethodMapping lMethod = lClass.getOrCreateMethodMapping(aMethod.getSrcName(), aMethod.getSrcDesc())
+							.setDeobfuscatedName(aMethod.getDstName(dstNamespace));
+
+					if (applyParameterMappings) {
+						for (MappingTree.MethodArgMapping aArg : aMethod.getArgs()) {
+							lMethod.getOrCreateParameterMapping(aArg.getLvIndex())
+									.setDeobfuscatedName(aArg.getDstName(dstNamespace));
+						}
+					}
+				}
+			}
+
+			return mappings;
+		}
+	}
+
+	public static class MappingsIO2MappingsUtils extends MappingsIO2Others {
+		public MutableTinyTree read() {
+			MappingTree tree = tree();
+			int dstNamesSize = tree.getDstNamespaces().size();
+			List<String> namespaces = new ArrayList<>();
+			namespaces.add(tree.getSrcNamespace());
+			namespaces.addAll(tree.getDstNamespaces());
+			Map<String, String> properties = new HashMap<>();
+
+			for (Map.Entry<String, String> entry : tree.getMetadata()) {
+				properties.put(entry.getKey(), entry.getValue());
+			}
+
+			MutableTinyTree out = MappingsUtils.create(MutableTinyMetadata.create(2, 0, namespaces, properties));
+
+			for (MappingTree.ClassMapping aClass : tree.getClasses()) {
+				MutableClassDef classDef = out.getOrCreateClass(aClass.getSrcName());
+				classDef.setComment(aClass.getComment());
+
+				for (int i = 0; i < dstNamesSize; i++) {
+					classDef.setName(i + 1, aClass.getDstName(i));
+				}
+
+				for (MappingTree.MethodMapping aMethod : aClass.getMethods()) {
+					MutableMethodDef methodDef = classDef.getOrCreateMethod(aMethod.getSrcName(), aMethod.getSrcDesc());
+					methodDef.setComment(aMethod.getComment());
+
+					for (int i = 0; i < dstNamesSize; i++) {
+						methodDef.setName(i + 1, aMethod.getDstName(i));
+					}
+
+					for (MappingTree.MethodArgMapping aMethodArg : aMethod.getArgs()) {
+						MutableParameterDef parameterDef = methodDef.getOrCreateParameter(aMethodArg.getLvIndex(), aMethodArg.getSrcName());
+						parameterDef.setComment(aMethodArg.getComment());
+
+						for (int i = 0; i < dstNamesSize; i++) {
+							parameterDef.setName(i + 1, aMethodArg.getDstName(i));
+						}
+					}
+				}
+
+				for (MappingTree.FieldMapping aField : aClass.getFields()) {
+					MutableFieldDef fieldDef = classDef.getOrCreateField(aField.getSrcName(), aField.getSrcDesc());
+					fieldDef.setComment(aField.getComment());
+
+					for (int i = 0; i < dstNamesSize; i++) {
+						fieldDef.setName(i + 1, aField.getDstName(i));
+					}
+				}
+			}
+
+			return out;
+		}
+	}
+}
diff --git a/src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingsSpecification.groovy b/src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingsSpecification.groovy
index 5c087a9d..64a37b5f 100644
--- a/src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingsSpecification.groovy
+++ b/src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingsSpecification.groovy
@@ -109,11 +109,6 @@ abstract class LayeredMappingsSpecification extends Specification implements Lay
         }
 
         @Override
-        File workingDirectory() {
-            return tempDir
-        }
-
-        @Override
         File workingDirectory(String name) {
             return new File(tempDir, name)
         }