Merge remote-tracking branch 'upstream/exp/1.13' into dev/1.13

# Conflicts:
#	build.gradle
#	gradle/libs.versions.toml
#	src/main/java/net/fabricmc/loom/LoomGradleExtension.java
#	src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
#	src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java
#	src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionImpl.java
#	src/main/java/net/fabricmc/loom/task/RemapJarTask.java

build.gradle

@@ -23,7 +23,7 @@ tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
 }
 
 group = "dev.architectury"
-def baseVersion = '1.12'
+def baseVersion = '1.13'
 
 def ENV = System.getenv()
 def runNumber = ENV.GITHUB_RUN_NUMBER ?: "9999"
@@ -147,6 +147,7 @@ dependencies {
 
 	// source code remapping
 	implementation libs.fabric.mercury
+	implementation libs.fabric.mercury.mixin
 
 	implementation libs.fabric.unpick
 	implementation libs.fabric.unpick.utils

gradle/libs.versions.toml

@@ -8,7 +8,8 @@ tiny-remapper = "0.12.0"
 clazz-tweaker = "0.1.1"
 mapping-io = "0.7.1"
 lorenz-tiny = "4.0.2"
-mercury = "0.1.4.17"
+mercury = "0.4.3"
+mercury-mixin = "0.2.1"
 loom-native = "0.2.0"
 unpick = "3.0.0-beta.9"
 
@@ -44,6 +45,7 @@ fabric-clazz-tweaker = { module = "net.fabricmc:class-tweaker", version.ref = "c
 fabric-mapping-io = { module = "net.fabricmc:mapping-io", version.ref = "mapping-io" }
 fabric-lorenz-tiny = { module = "net.fabricmc:lorenz-tiny", version.ref = "lorenz-tiny" }
 fabric-mercury = { module = "dev.architectury:mercury", version.ref = "mercury" }
+fabric-mercury-mixin = { module = "net.fabricmc:mercurymixin", version.ref = "mercury-mixin" }
 fabric-loom-nativelib = { module = "net.fabricmc:fabric-loom-native", version.ref = "loom-native" }
 fabric-unpick = { module = "net.fabricmc.unpick:unpick", version.ref = "unpick" }
 fabric-unpick-utils = { module = "net.fabricmc.unpick:unpick-format-utils", version.ref = "unpick" }

src/main/java/net/fabricmc/loom/LoomGradleExtension.java

@@ -46,7 +46,6 @@ import org.jetbrains.annotations.ApiStatus;
 import net.fabricmc.loom.api.LoomGradleExtensionAPI;
 import net.fabricmc.loom.api.mappings.layered.MappingsNamespace;
 import net.fabricmc.loom.configuration.InstallerData;
-import net.fabricmc.loom.configuration.LoomDependencyManager;
 import net.fabricmc.loom.configuration.accesswidener.AccessWidenerFile;
 import net.fabricmc.loom.configuration.providers.mappings.LayeredMappingsFactory;
 import net.fabricmc.loom.configuration.providers.mappings.MappingConfiguration;
@@ -77,10 +76,6 @@ public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 
 	InstallerData getInstallerData();
 
-	void setDependencyManager(LoomDependencyManager dependencyManager);
-
-	LoomDependencyManager getDependencyManager();
-
 	MinecraftMetadataProvider getMetadataProvider();
 
 	void setMetadataProvider(MinecraftMetadataProvider metadataProvider);
@@ -158,6 +153,16 @@ public interface LoomGradleExtension extends LoomGradleExtensionAPI {
 	 */
 	boolean isCollectingDependencyVerificationMetadata();
 
+	/**
+	 * When enabled do not remap the output jars.
+	 */
+	boolean dontRemapOutputs();
+
+	/**
+	 * When enabled disable all forms of remapping.
+	 */
+	boolean disableObfuscation();
+
 	// ===================
 	//  Architectury Loom
 	// ===================

src/main/java/net/fabricmc/loom/api/ModSettings.java

@@ -197,4 +197,10 @@ public abstract class ModSettings implements Named {
 
 		project.apply(Map.of("plugin", LoomCompanionGradlePlugin.NAME));
 	}
+
+	// DO NOT USE THIS!!!
+	// Added back because the Minecraft dev plugin uses it.
+	@ApiStatus.Internal
+	@Deprecated(forRemoval = true)
+	public abstract ListProperty<SourceSetReference> getModSourceSets();
 }

src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java

@@ -65,6 +65,7 @@ import org.gradle.api.tasks.TaskContainer;
 import org.gradle.api.tasks.compile.JavaCompile;
 import org.gradle.api.tasks.javadoc.Javadoc;
 import org.gradle.api.tasks.testing.Test;
+import org.jetbrains.annotations.Nullable;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.api.InterfaceInjectionExtensionAPI;
@@ -137,9 +138,8 @@ public abstract class CompileConfiguration implements Runnable {
 					setupMinecraft(configContext);
 				}
 
-				LoomDependencyManager dependencyManager = new LoomDependencyManager();
+				var dependencyManager = new LoomDependencyManager(getProject(), serviceFactory, extension);
-				extension.setDependencyManager(dependencyManager);
+				dependencyManager.handleDependencies();
-				dependencyManager.handleDependencies(getProject(), serviceFactory);
 			} catch (Exception e) {
 				ExceptionUtil.processException(e, DaemonUtils.Context.fromProject(getProject()));
 				disownLock();
@@ -222,6 +222,7 @@ public abstract class CompileConfiguration implements Runnable {
 		extension.setMinecraftProvider(minecraftProvider);
 		minecraftProvider.provide();
 
+		if (!extension.disableObfuscation()) {
 			// Realise the dependencies without actually resolving them, this forces any lazy providers to be created, populating the layered mapping factories.
 			project.getConfigurations().getByName(Configurations.MAPPINGS).getDependencies().toArray();
 
@@ -244,6 +245,7 @@ public abstract class CompileConfiguration implements Runnable {
 
 			mappingConfiguration.setupPost(project);
 			mappingConfiguration.applyToProject(getProject(), mappingsDep);
+		}
 
 		if (extension.isForgeLike()) {
 			extension.setForgeRunsProvider(ForgeRunsProvider.create(project));
@@ -254,7 +256,7 @@ public abstract class CompileConfiguration implements Runnable {
 		}
 
 		// Provide the remapped mc jars
-		final IntermediaryMinecraftProvider<?> intermediaryMinecraftProvider = jarConfiguration.createIntermediaryMinecraftProvider(project);
+		@Nullable IntermediaryMinecraftProvider<?> intermediaryMinecraftProvider = extension.disableObfuscation() ? null : jarConfiguration.createIntermediaryMinecraftProvider(project);
 		NamedMinecraftProvider<?> namedMinecraftProvider = jarConfiguration.createNamedMinecraftProvider(project);
 
 		registerGameProcessors(configContext);
@@ -267,8 +269,10 @@ public abstract class CompileConfiguration implements Runnable {
 
 		final var provideContext = new AbstractMappedMinecraftProvider.ProvideContext(true, extension.refreshDeps(), configContext);
 
+		if (intermediaryMinecraftProvider != null) {
 			extension.setIntermediaryMinecraftProvider(intermediaryMinecraftProvider);
 			intermediaryMinecraftProvider.provide(provideContext);
+		}
 
 		extension.setNamedMinecraftProvider(namedMinecraftProvider);
 		namedMinecraftProvider.provide(provideContext);

src/main/java/net/fabricmc/loom/configuration/LoomConfigurations.java

@@ -135,17 +135,19 @@ public abstract class LoomConfigurations implements Runnable {
 
 		extendsFrom(JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME, Constants.Configurations.MAPPING_CONSTANTS);
 
+		if (!extension.disableObfuscation()) {
 			register(Constants.Configurations.MAPPINGS, Role.RESOLVABLE);
 			register(Constants.Configurations.MAPPINGS_FINAL, Role.RESOLVABLE);
+			extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.MAPPINGS_FINAL);
+			extendsFrom(JavaPlugin.TEST_RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.MAPPINGS_FINAL);
+
+			extension.createRemapConfigurations(SourceSetHelper.getMainSourceSet(getProject()));
+		}
+
 		register(Constants.Configurations.LOOM_DEVELOPMENT_DEPENDENCIES, Role.RESOLVABLE);
 		register(Constants.Configurations.LOCAL_RUNTIME, Role.RESOLVABLE);
 		extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.LOCAL_RUNTIME);
 
-		extension.createRemapConfigurations(SourceSetHelper.getMainSourceSet(getProject()));
-
-		extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.MAPPINGS_FINAL);
-		extendsFrom(JavaPlugin.TEST_RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.MAPPINGS_FINAL);
-
 		extendsFrom(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME, Constants.Configurations.MINECRAFT_RUNTIME_LIBRARIES);
 
 		// Add the dev time dependencies

src/main/java/net/fabricmc/loom/configuration/LoomDependencyManager.java

@@ -31,9 +31,16 @@ import net.fabricmc.loom.configuration.mods.ModConfigurationRemapper;
 import net.fabricmc.loom.util.SourceRemapper;
 import net.fabricmc.loom.util.service.ServiceFactory;
 
-public class LoomDependencyManager {
+public record LoomDependencyManager(Project project, ServiceFactory serviceFactory, LoomGradleExtension extension) {
-	public void handleDependencies(Project project, ServiceFactory serviceFactory) {
+	public void handleDependencies() {
-		project.getLogger().info(":setting up loom dependencies");
+		if (extension.disableObfuscation()) {
+			handleNonRemapDependencies();
+		} else {
+			handleRemapDependencies();
+		}
+	}
+
+	private void handleRemapDependencies() {
 		LoomGradleExtension extension = LoomGradleExtension.get(project);
 
 		SourceRemapper sourceRemapper = new SourceRemapper(project, serviceFactory, true);
@@ -52,4 +59,8 @@ public class LoomDependencyManager {
 			}
 		}
 	}
+
+	private void handleNonRemapDependencies() {
+		// TODO debof - do we need to do anything?
+	}
 }

src/main/java/net/fabricmc/loom/configuration/decompile/DecompileConfiguration.java

@@ -27,7 +27,6 @@ package net.fabricmc.loom.configuration.decompile;
 import org.gradle.api.Project;
 
 import net.fabricmc.loom.LoomGradleExtension;
-import net.fabricmc.loom.configuration.providers.mappings.MappingConfiguration;
 import net.fabricmc.loom.configuration.providers.minecraft.MinecraftJar;
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.MappedMinecraftProvider;
 
@@ -37,13 +36,11 @@ public abstract class DecompileConfiguration<T extends MappedMinecraftProvider>
 	protected final Project project;
 	protected final T minecraftProvider;
 	protected final LoomGradleExtension extension;
-	protected final MappingConfiguration mappingConfiguration;
 
 	public DecompileConfiguration(Project project, T minecraftProvider) {
 		this.project = project;
 		this.minecraftProvider = minecraftProvider;
 		this.extension = LoomGradleExtension.get(project);
-		this.mappingConfiguration = extension.getMappingConfiguration();
 	}
 
 	public abstract String getTaskName(MinecraftJar.Type type);

src/main/java/net/fabricmc/loom/configuration/processors/MinecraftJarProcessorManager.java

@@ -66,7 +66,15 @@ public final class MinecraftJarProcessorManager {
 			processors.add(project.getObjects().newInstance(LegacyJarProcessorWrapper.class, legacyProcessor));
 		}
 
-		return MinecraftJarProcessorManager.create(processors, SpecContextImpl.create(project));
+		SpecContext specContext;
+
+		if (extension.disableObfuscation()) {
+			specContext = SpecContextDebofImpl.create();
+		} else {
+			specContext = SpecContextRemappedImpl.create(project);
+		}
+
+		return MinecraftJarProcessorManager.create(processors, specContext);
 	}
 
 	@Nullable

src/main/java/net/fabricmc/loom/configuration/processors/ModJavadocProcessor.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2022 FabricMC
+ * Copyright (c) 2022-2025 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
@@ -34,6 +34,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 
 import javax.inject.Inject;
@@ -50,7 +51,12 @@ import net.fabricmc.loom.api.processor.SpecContext;
 import net.fabricmc.loom.util.Checksum;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.fmj.FabricModJson;
+import net.fabricmc.mappingio.MappedElementKind;
 import net.fabricmc.mappingio.MappingReader;
+import net.fabricmc.mappingio.MappingUtil;
+import net.fabricmc.mappingio.MappingVisitor;
+import net.fabricmc.mappingio.adapter.ForwardingMappingVisitor;
+import net.fabricmc.mappingio.adapter.MappingNsRenamer;
 import net.fabricmc.mappingio.tree.MappingTree;
 import net.fabricmc.mappingio.tree.MemoryMappingTree;
 
@@ -127,7 +133,16 @@ public abstract class ModJavadocProcessor implements MinecraftJarProcessor<ModJa
 				mappingsHash = Checksum.of(data).sha1().hex();
 
 				try (Reader reader = new InputStreamReader(new ByteArrayInputStream(data))) {
-					MappingReader.read(reader, mappings);
+					// Replace the default fallback namespaces with intermediary and named
+					// if the format doesn't have them (this includes the Enigma format, which we want to
+					// support since it's produced by ModEnigmaTask).
+					final Map<String, String> fallbackNamespaceReplacements = Map.of(
+							MappingUtil.NS_SOURCE_FALLBACK, MappingsNamespace.INTERMEDIARY.toString(),
+							MappingUtil.NS_TARGET_FALLBACK, MappingsNamespace.NAMED.toString()
+					);
+					final MappingNsRenamer renamer = new MappingNsRenamer(mappings, fallbackNamespaceReplacements);
+					final DstNameCheckingVisitor checker = new DstNameCheckingVisitor(modId, renamer);
+					MappingReader.read(reader, checker);
 				}
 			} catch (IOException e) {
 				throw new UncheckedIOException("Failed to read javadoc from mod: " + modId, e);
@@ -137,10 +152,6 @@ public abstract class ModJavadocProcessor implements MinecraftJarProcessor<ModJa
 				throw new IllegalStateException("Javadoc provided by mod (%s) must be have an intermediary source namespace".formatted(modId));
 			}
 
-			if (!mappings.getDstNamespaces().isEmpty()) {
-				throw new IllegalStateException("Javadoc provided by mod (%s) must not contain any dst names".formatted(modId));
-			}
-
 			return new ModJavadoc(modId, mappings, mappingsHash);
 		}
 
@@ -214,4 +225,18 @@ public abstract class ModJavadocProcessor implements MinecraftJarProcessor<ModJa
 			return "ModJavadoc{modId='%s', mappingsHash='%s'}".formatted(modId, mappingsHash);
 		}
 	}
+
+	private static final class DstNameCheckingVisitor extends ForwardingMappingVisitor {
+		private final String modId;
+
+		DstNameCheckingVisitor(String modId, MappingVisitor next) {
+			super(next);
+			this.modId = modId;
+		}
+
+		@Override
+		public void visitDstName(MappedElementKind targetKind, int namespace, String name) {
+			throw new IllegalStateException("Javadoc provided by mod (%s) must not contain any dst names".formatted(modId));
+		}
+	}
 }

src/main/java/net/fabricmc/loom/configuration/processors/SpecContextDebofImpl.java

@@ -0,0 +1,48 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2025 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 net.fabricmc.loom.configuration.processors;
+
+import java.util.List;
+
+import net.fabricmc.loom.api.processor.SpecContext;
+import net.fabricmc.loom.util.fmj.FabricModJson;
+
+// TODO debof - fixme
+public record SpecContextDebofImpl(List<FabricModJson> modDependencies,
+									List<FabricModJson> localMods) implements SpecContext {
+	public static SpecContext create() {
+		return new SpecContextDebofImpl(List.of(), List.of());
+	}
+
+	@Override
+	public List<FabricModJson> modDependenciesCompileRuntime() {
+		return List.of();
+	}
+
+	@Override
+	public List<FabricModJson> modDependenciesCompileRuntimeClient() {
+		return List.of();
+	}
+}

src/main/java/net/fabricmc/loom/configuration/processors/SpecContextRemappedImpl.java

@@ -56,18 +56,18 @@ import net.fabricmc.loom.util.fmj.FabricModJsonHelpers;
  * @param localMods Mods found in the current project.
  * @param compileRuntimeMods Dependent mods found in both the compile and runtime classpath.
  */
-public record SpecContextImpl(
+public record SpecContextRemappedImpl(
 		List<FabricModJson> modDependencies,
 		List<FabricModJson> localMods,
 		List<ModHolder> compileRuntimeMods) implements SpecContext {
-	public static SpecContextImpl create(Project project) {
+	public static SpecContextRemappedImpl create(Project project) {
 		return create(new SpecContextProjectView.Impl(project, LoomGradleExtension.get(project)));
 	}
 
 	@VisibleForTesting
-	public static SpecContextImpl create(SpecContextProjectView projectView) {
+	public static SpecContextRemappedImpl create(SpecContextProjectView projectView) {
 		AsyncCache<List<FabricModJson>> fmjCache = new AsyncCache<>();
-		return new SpecContextImpl(
+		return new SpecContextRemappedImpl(
 				getDependentMods(projectView, fmjCache),
 				projectView.getMods(),
 				getCompileRuntimeMods(projectView, fmjCache)

src/main/java/net/fabricmc/loom/configuration/providers/minecraft/mapped/AbstractMappedMinecraftProvider.java

@@ -182,16 +182,20 @@ public abstract class AbstractMappedMinecraftProvider<M extends MinecraftProvide
 	}
 
 	protected String getName(MinecraftJar.Type type) {
-		final String intermediateName = extension.getIntermediateMappingsProvider().getName();
-
 		var sj = new StringJoiner("-");
 		sj.add("minecraft");
 		sj.add(type.toString());
 
+		if (!extension.disableObfuscation()) {
 			// Include the intermediate mapping name if it's not the default intermediary
+			final String intermediateName = extension.getIntermediateMappingsProvider().getName();
+
 			if (!intermediateName.equals(IntermediaryMappingsProvider.NAME)) {
 				sj.add(intermediateName);
 			}
+		} else {
+			sj.add("deobf");
+		}
 
 		if (getTargetNamespace() != MappingsNamespace.NAMED) {
 			sj.add(getTargetNamespace().name());
@@ -201,6 +205,10 @@ public abstract class AbstractMappedMinecraftProvider<M extends MinecraftProvide
 	}
 
 	protected String getVersion() {
+		if (extension.disableObfuscation()) {
+			return extension.getMinecraftProvider().minecraftVersion();
+		}
+
 		return "%s-%s".formatted(extension.getMinecraftProvider().minecraftVersion(), extension.getMappingConfiguration().mappingsIdentifier());
 	}
 
@@ -251,7 +259,15 @@ public abstract class AbstractMappedMinecraftProvider<M extends MinecraftProvide
 		}
 	}
 
-	private void remapJar(RemappedJars remappedJars, ConfigContext configContext) throws IOException {
+	protected void remapJar(RemappedJars remappedJars, ConfigContext configContext) throws IOException {
+		if (extension.disableObfuscation()) {
+			// TODO debof - can we skip this?
+			Files.createDirectories(remappedJars.outputJarPath().getParent());
+			Files.copy(remappedJars.inputJar(), remappedJars.outputJarPath(), StandardCopyOption.REPLACE_EXISTING);
+			getMavenHelper(remappedJars.type()).savePom();
+			return;
+		}
+
 		final MappingConfiguration mappingConfiguration = extension.getMappingConfiguration();
 		final String fromM = remappedJars.sourceNamespace().toString();
 		final String toM = getTargetNamespace().toString();

src/main/java/net/fabricmc/loom/configuration/providers/minecraft/mapped/IntermediaryMinecraftProvider.java

@@ -41,6 +41,10 @@ import net.fabricmc.tinyremapper.TinyRemapper;
 public abstract sealed class IntermediaryMinecraftProvider<M extends MinecraftProvider> extends AbstractMappedMinecraftProvider<M> permits IntermediaryMinecraftProvider.MergedImpl, IntermediaryMinecraftProvider.LegacyMergedImpl, IntermediaryMinecraftProvider.SingleJarImpl, IntermediaryMinecraftProvider.SplitImpl {
 	public IntermediaryMinecraftProvider(Project project, M minecraftProvider) {
 		super(project, minecraftProvider);
+
+		if (extension.disableObfuscation()) {
+			throw new UnsupportedOperationException("Intermediary Minecraft providers cannot be used when obfuscation is disabled");
+		}
 	}
 
 	@Override

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java

@@ -285,6 +285,10 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public Dependency officialMojangMappings() {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot use Mojang mappings in a non-obfuscated environment");
+		}
+
 		if (layeredSpecBuilderScope.get()) {
 			throw new IllegalStateException("Use `officialMojangMappings()` when configuring layered mappings, not the extension method `loom.officialMojangMappings()`");
 		}
@@ -294,6 +298,10 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public Dependency layered(Action<LayeredMappingSpecBuilder> action) {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot configure layered mappings in a non-obfuscated environment");
+		}
+
 		if (hasEvaluatedLayeredMappings) {
 			throw new IllegalStateException("Layered mappings have already been evaluated");
 		}
@@ -341,6 +349,10 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public SetProperty<String> getKnownIndyBsms() {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot configure known indyBsms in a non-obfuscated environment");
+		}
+
 		return knownIndyBsms;
 	}
 
@@ -376,6 +388,10 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public IntermediateMappingsProvider getIntermediateMappingsProvider() {
+		if (LoomGradleExtension.get(getProject()).disableObfuscation()) {
+			throw new UnsupportedOperationException("Cannot get intermediate mappings provider in a non-obfuscated environment");
+		}
+
 		return intermediateMappingsProvider.get();
 	}
 
@@ -389,11 +405,15 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 		T provider = getProject().getObjects().newInstance(clazz);
 		configureIntermediateMappingsProviderInternal(provider);
 		action.execute(provider);
-		intermediateMappingsProvider.set(provider);
+		setIntermediateMappingsProvider(provider);
 	}
 
 	@Override
 	public File getMappingsFile() {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot get mappings file in a non-obfuscated environment");
+		}
+
 		return LoomGradleExtension.get(getProject()).getMappingConfiguration().tinyMappings.toFile();
 	}
 
@@ -468,11 +488,19 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public NamedDomainObjectList<RemapConfigurationSettings> getRemapConfigurations() {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot get remap configurations in a non-obfuscated environment");
+		}
+
 		return remapConfigurations;
 	}
 
 	@Override
 	public RemapConfigurationSettings addRemapConfiguration(String name, Action<RemapConfigurationSettings> action) {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot add remap configuration in a non-obfuscated environment");
+		}
+
 		final RemapConfigurationSettings configurationSettings = getProject().getObjects().newInstance(RemapConfigurationSettings.class, name);
 
 		// TODO remove in 2.0, this is a fallback to mimic the previous (Broken) behaviour
@@ -487,11 +515,19 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 
 	@Override
 	public void createRemapConfigurations(SourceSet sourceSet) {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot create remap configurations in a non-obfuscated environment");
+		}
+
 		RemapConfigurations.setupForSourceSet(getProject(), sourceSet);
 	}
 
 	@Override
 	public <T extends RemapperParameters> void addRemapperExtension(Class<? extends RemapperExtension<T>> remapperExtensionClass, Class<T> parametersClass, Action<T> parameterAction) {
+		if (notObfuscated()) {
+			throw new UnsupportedOperationException("Cannot add remapper extension in a non-obfuscated environment");
+		}
+
 		final ObjectFactory objectFactory = getProject().getObjects();
 		final RemapperExtensionHolder holder;
 
@@ -519,6 +555,10 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 		return jars;
 	}
 
+	private boolean notObfuscated() {
+		return LoomGradleExtension.get(getProject()).disableObfuscation();
+	}
+
 	@Override
 	public void silentMojangMappingsLicense() {
 		try {

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionImpl.java

@@ -42,6 +42,7 @@ import org.gradle.api.configuration.BuildFeatures;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.provider.ListProperty;
+import org.gradle.api.provider.Property;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.api.ForgeExtensionAPI;
@@ -62,10 +63,12 @@ import net.fabricmc.loom.configuration.providers.minecraft.mapped.IntermediaryMi
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.MojangMappedMinecraftProvider;
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.NamedMinecraftProvider;
 import net.fabricmc.loom.configuration.providers.minecraft.mapped.SrgMinecraftProvider;
+import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.Lazy;
 import net.fabricmc.loom.util.ModPlatform;
 import net.fabricmc.loom.util.download.Download;
 import net.fabricmc.loom.util.download.DownloadBuilder;
+import net.fabricmc.loom.util.gradle.GradleUtils;
 
 public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl implements LoomGradleExtension {
 	private final Project project;
@@ -89,6 +92,8 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 	private final boolean configurationCacheActive;
 	private final boolean isolatedProjectsActive;
 	private final boolean isCollectingDependencyVerificationMetadata;
+	private final Property<Boolean> disableObfuscation;
+	private final Property<Boolean> dontRemap;
 
 	// +-------------------+
 	// | Architectury Loom |
@@ -129,6 +134,14 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 		configurationCacheActive = getBuildFeatures().getConfigurationCache().getActive().get();
 		isolatedProjectsActive = getBuildFeatures().getIsolatedProjects().getActive().get();
 		isCollectingDependencyVerificationMetadata = !project.getGradle().getStartParameter().getWriteDependencyVerifications().isEmpty();
+		disableObfuscation = project.getObjects().property(Boolean.class);
+		dontRemap = project.getObjects().property(Boolean.class);
+
+		disableObfuscation.set(project.provider(() -> GradleUtils.getBooleanProperty(getProject(), Constants.Properties.DISABLE_OBFUSCATION)));
+		disableObfuscation.finalizeValueOnRead();
+
+		dontRemap.set(disableObfuscation.map(notObfuscated -> notObfuscated || GradleUtils.getBooleanProperty(getProject(), Constants.Properties.DONT_REMAP)));
+		dontRemap.finalizeValueOnRead();
 
 		if (refreshDeps) {
 			project.getLogger().lifecycle("Refresh dependencies is in use, loom will be significantly slower.");
@@ -149,16 +162,6 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 		return loomFiles;
 	}
 
-	@Override
-	public void setDependencyManager(LoomDependencyManager dependencyManager) {
-		this.dependencyManager = dependencyManager;
-	}
-
-	@Override
-	public LoomDependencyManager getDependencyManager() {
-		return Objects.requireNonNull(dependencyManager, "Cannot get LoomDependencyManager before it has been setup");
-	}
-
 	@Override
 	public MinecraftMetadataProvider getMetadataProvider() {
 		return Objects.requireNonNull(metadataProvider, "Cannot get MinecraftMetadataProvider before it has been setup");
@@ -181,11 +184,19 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 
 	@Override
 	public MappingConfiguration getMappingConfiguration() {
+		if (disableObfuscation()) {
+			throw new UnsupportedOperationException("Cannot get mappings configuration in a non-obfuscated environment");
+		}
+
 		return Objects.requireNonNull(mappingConfiguration, "Cannot get MappingsProvider before it has been setup");
 	}
 
 	@Override
 	public void setMappingConfiguration(MappingConfiguration mappingConfiguration) {
+		if (disableObfuscation()) {
+			throw new UnsupportedOperationException("Cannot set mappings configuration in a non-obfuscated environment");
+		}
+
 		this.mappingConfiguration = mappingConfiguration;
 	}
 
@@ -320,6 +331,10 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 
 	@Override
 	public Collection<LayeredMappingsFactory> getLayeredMappingFactories() {
+		if (disableObfuscation()) {
+			throw new UnsupportedOperationException("Cannot get layered mapping factories in a non-obfuscated environment");
+		}
+
 		hasEvaluatedLayeredMappings = true;
 		return Collections.unmodifiableCollection(layeredMappingsDependencyMap.values());
 	}
@@ -351,6 +366,16 @@ public abstract class LoomGradleExtensionImpl extends LoomGradleExtensionApiImpl
 		return isCollectingDependencyVerificationMetadata;
 	}
 
+	@Override
+	public boolean dontRemapOutputs() {
+		return dontRemap.get();
+	}
+
+	@Override
+	public boolean disableObfuscation() {
+		return disableObfuscation.get();
+	}
+
 	@Override
 	public ForgeExtensionAPI getForge() {
 		ModPlatform.assertPlatform(this, ModPlatform.FORGE);

src/main/java/net/fabricmc/loom/task/AbstractRemapJarTask.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2021 FabricMC
+ * Copyright (c) 2021-2025 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
@@ -27,7 +27,9 @@ package net.fabricmc.loom.task;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -56,6 +58,8 @@ import org.gradle.workers.WorkParameters;
 import org.gradle.workers.WorkQueue;
 import org.gradle.workers.WorkerExecutor;
 import org.jetbrains.annotations.ApiStatus;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.api.mappings.layered.MappingsNamespace;
@@ -64,6 +68,7 @@ import net.fabricmc.loom.task.service.ClientEntriesService;
 import net.fabricmc.loom.task.service.JarManifestService;
 import net.fabricmc.loom.util.Check;
 import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.ExceptionUtil;
 import net.fabricmc.loom.util.ZipReprocessorUtil;
 import net.fabricmc.loom.util.ZipUtils;
 import net.fabricmc.loom.util.gradle.SourceSetHelper;
@@ -116,6 +121,7 @@ public abstract class AbstractRemapJarTask extends Jar {
 
 	@Inject
 	public AbstractRemapJarTask() {
+		from(getProject().zipTree(getInputFile()));
 		getSourceNamespace().convention(MappingsNamespace.NAMED.toString()).finalizeValueOnRead();
 		getTargetNamespace().convention(getProject().provider(() -> IntermediaryNamespaces.runtimeIntermediary(getProject()))).finalizeValueOnRead();
 		getIncludesClientOnlyClasses().convention(false).finalizeValueOnRead();
@@ -134,17 +140,11 @@ public abstract class AbstractRemapJarTask extends Jar {
 		usesService(jarManifestServiceProvider);
 	}
 
-	@Override
-	protected void copy() {
-		// Skip the default copy behaviour of AbstractCopyTask.
-	}
-
 	public final <P extends AbstractRemapParams> void submitWork(Class<? extends AbstractRemapAction<P>> workAction, Action<P> action) {
 		final WorkQueue workQueue = getWorkerExecutor().noIsolation();
 
 		workQueue.submit(workAction, params -> {
-			params.getInputFile().set(getInputFile());
+			params.getArchiveFile().set(getArchiveFile());
-			params.getOutputFile().set(getArchiveFile());
 
 			params.getSourceNamespace().set(getSourceNamespace());
 			params.getTargetNamespace().set(getTargetNamespace());
@@ -182,8 +182,7 @@ public abstract class AbstractRemapJarTask extends Jar {
 	protected abstract Provider<? extends ClientEntriesService.Options> getClientOnlyEntriesOptionsProvider(SourceSet clientSourceSet);
 
 	public interface AbstractRemapParams extends WorkParameters {
-		RegularFileProperty getInputFile();
+		RegularFileProperty getArchiveFile();
-		RegularFileProperty getOutputFile();
 
 		Property<String> getSourceNamespace();
 		Property<String> getTargetNamespace();
@@ -218,15 +217,34 @@ public abstract class AbstractRemapJarTask extends Jar {
 	}
 
 	public abstract static class AbstractRemapAction<T extends AbstractRemapParams> implements WorkAction<T> {
-		protected final Path inputFile;
+		private static final Logger LOGGER = LoggerFactory.getLogger(AbstractRemapAction.class);
 		protected final Path outputFile;
 
 		@Inject
 		public AbstractRemapAction() {
-			inputFile = getParameters().getInputFile().getAsFile().get().toPath();
+			outputFile = getParameters().getArchiveFile().getAsFile().get().toPath();
-			outputFile = getParameters().getOutputFile().getAsFile().get().toPath();
 		}
 
+		@Override
+		public final void execute() {
+			try {
+				Path tempInput = Files.createTempFile("loom-remapJar-", "-input.jar");
+				Files.copy(outputFile, tempInput, StandardCopyOption.REPLACE_EXISTING);
+				execute(tempInput);
+				Files.delete(tempInput);
+			} catch (Exception e) {
+				try {
+					Files.deleteIfExists(outputFile);
+				} catch (IOException ex) {
+					LOGGER.error("Failed to delete output file", ex);
+				}
+
+				throw ExceptionUtil.createDescriptiveWrapper(RuntimeException::new, "Failed to remap " + outputFile.toAbsolutePath(), e);
+			}
+		}
+
+		protected abstract void execute(Path inputFile) throws IOException;
+
 		protected void modifyJarManifest() throws IOException {
 			int count = ZipUtils.transform(outputFile, Map.of(Constants.Manifest.PATH, bytes -> {
 				var manifest = new Manifest(new ByteArrayInputStream(bytes));

src/main/java/net/fabricmc/loom/task/GenerateSourcesTask.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2016-2022 FabricMC
+ * Copyright (c) 2016-2025 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
@@ -422,6 +422,13 @@ public abstract class GenerateSourcesTask extends AbstractLoomTask {
 			sj.add(unpick.getUnpickCacheKey());
 		}
 
+		SourceMappingsService mappingsService = serviceFactory.get(getMappings());
+		String mappingsHash = mappingsService.getProcessorHash();
+
+		if (mappingsHash != null) {
+			sj.add(mappingsHash);
+		}
+
 		getLogger().info("Decompile cache data: {}", sj);
 
 		return Checksum.of(sj.toString()).sha256().hex();

src/main/java/net/fabricmc/loom/task/LoomTasks.java

@@ -49,6 +49,7 @@ import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.LoomVersions;
 import net.fabricmc.loom.util.Platform;
 import net.fabricmc.loom.util.gradle.GradleUtils;
+import net.fabricmc.loom.util.gradle.SourceSetHelper;
 
 public abstract class LoomTasks implements Runnable {
 	@Inject
@@ -59,10 +60,26 @@ public abstract class LoomTasks implements Runnable {
 
 	@Override
 	public void run() {
+		SourceSetHelper.getSourceSets(getProject()).all(sourceSet -> {
+			if (SourceSetHelper.isMainSourceSet(sourceSet)) {
 				getTasks().register("migrateMappings", MigrateMappingsTask.class, t -> {
 					t.setDescription("Migrates mappings to a new version.");
 				});
 
+				return;
+			}
+
+			if (!SourceSetHelper.getFirstSrcDir(sourceSet).exists()) {
+				return;
+			}
+
+			getTasks().register(sourceSet.getTaskName("migrate", "mappings"), MigrateMappingsTask.class, t -> {
+				t.setDescription("Migrates mappings to a new version.");
+				t.getInputDir().set(SourceSetHelper.getFirstSrcDir(sourceSet));
+				t.getOutputDir().convention(getProject().getLayout().getProjectDirectory().dir(sourceSet.getTaskName("remapped", "src")));
+			});
+		});
+
 		var generateLog4jConfig = getTasks().register("generateLog4jConfig", GenerateLog4jConfigTask.class, t -> {
 			t.setDescription("Generate the log4j config file");
 		});

src/main/java/net/fabricmc/loom/task/MigrateMappingsTask.java

@@ -24,17 +24,22 @@
 
 package net.fabricmc.loom.task;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
+
 import org.gradle.api.file.DirectoryProperty;
 import org.gradle.api.provider.Property;
 import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.InputDirectory;
 import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.OutputDirectory;
+import org.gradle.api.tasks.SkipWhenEmpty;
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.api.tasks.UntrackedTask;
 import org.gradle.api.tasks.options.Option;
 
 import net.fabricmc.loom.task.service.MigrateMappingsService;
+import net.fabricmc.loom.util.DeletingFileVisitor;
 import net.fabricmc.loom.util.service.ScopedServiceFactory;
 
 @UntrackedTask(because = "Always rerun this task.")
@@ -44,6 +49,7 @@ public abstract class MigrateMappingsTask extends AbstractLoomTask {
 	public abstract Property<String> getMappings();
 
 	@InputDirectory
+	@SkipWhenEmpty
 	@Option(option = "input", description = "Java source file directory")
 	public abstract DirectoryProperty getInputDir();
 
@@ -51,6 +57,10 @@ public abstract class MigrateMappingsTask extends AbstractLoomTask {
 	@Option(option = "output", description = "Remapped source output directory")
 	public abstract DirectoryProperty getOutputDir();
 
+	@Input
+	@Option(option = "overrideInputsIHaveABackup", description = "Override input files with the remapped files")
+	public abstract Property<Boolean> getOverrideInputs();
+
 	@Nested
 	protected abstract Property<MigrateMappingsService.Options> getMigrationServiceOptions();
 
@@ -58,6 +68,7 @@ public abstract class MigrateMappingsTask extends AbstractLoomTask {
 		getInputDir().convention(getProject().getLayout().getProjectDirectory().dir("src/main/java"));
 		getOutputDir().convention(getProject().getLayout().getProjectDirectory().dir("remappedSrc"));
 		getMigrationServiceOptions().set(MigrateMappingsService.createOptions(getProject(), getMappings(), getInputDir(), getOutputDir()));
+		getOverrideInputs().convention(false);
 	}
 
 	@TaskAction
@@ -66,5 +77,13 @@ public abstract class MigrateMappingsTask extends AbstractLoomTask {
 			MigrateMappingsService service = serviceFactory.get(getMigrationServiceOptions().get());
 			service.migrateMapppings();
 		}
+
+		if (getOverrideInputs().get()) {
+			Path inputPath = getInputDir().getAsFile().get().toPath();
+			Path outputPath = getOutputDir().getAsFile().get().toPath();
+
+			DeletingFileVisitor.deleteDirectory(inputPath);
+			Files.move(outputPath, inputPath);
+		}
 	}
 }

src/main/java/net/fabricmc/loom/task/RemapJarTask.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2021-2024 FabricMC
+ * Copyright (c) 2021-2025 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
@@ -57,7 +57,6 @@ import org.gradle.api.tasks.InputFiles;
 import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.Optional;
 import org.gradle.api.tasks.SourceSet;
-import org.gradle.api.tasks.TaskAction;
 import org.gradle.api.tasks.TaskProvider;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
@@ -185,8 +184,10 @@ public abstract class RemapJarTask extends AbstractRemapJarTask {
 		getInjectedAccessWidenerPath().convention(LoomGradleExtension.get(getProject()).getAccessWidenerPath());
 	}
 
-	@TaskAction
+	@Override
-	public void run() {
+	protected void copy() {
+		super.copy();
+
 		submitWork(RemapAction.class, params -> {
 			if (getAddNestedDependencies().get()) {
 				params.getNestedJars().from(getNestedJars());
@@ -246,14 +247,16 @@ public abstract class RemapJarTask extends AbstractRemapJarTask {
 
 		private @Nullable TinyRemapperService tinyRemapperService;
 		private @Nullable TinyRemapper tinyRemapper;
+		private Path inputFile;
 
 		public RemapAction() {
 		}
 
 		@Override
-		public void execute() {
+		protected void execute(Path inputFile) throws IOException {
 			try (var serviceFactory = new ScopedServiceFactory()) {
 				LOGGER.info("Remapping {} to {}", inputFile, outputFile);
+				this.inputFile = inputFile;
 
 				this.tinyRemapperService = getParameters().getTinyRemapperServiceOptions().isPresent()
 						? serviceFactory.get(getParameters().getTinyRemapperServiceOptions().get())
@@ -306,20 +309,10 @@ public abstract class RemapJarTask extends AbstractRemapJarTask {
 				}
 
 				LOGGER.debug("Finished remapping {}", inputFile);
-			} catch (Exception e) {
-				try {
-					Files.deleteIfExists(outputFile);
-				} catch (IOException ex) {
-					LOGGER.error("Failed to delete output file", ex);
-				}
-
-				throw ExceptionUtil.createDescriptiveWrapper(RuntimeException::new, "Failed to remap", e);
 			}
 		}
 
 		private void prepare() {
-			final Path inputFile = getParameters().getInputFile().getAsFile().get().toPath();
-
 			if (tinyRemapperService != null) {
 				tinyRemapperService.getTinyRemapperForInputs().readInputsAsync(tinyRemapperService.getOrCreateTag(inputFile), inputFile);
 			}

src/main/java/net/fabricmc/loom/task/RemapSourcesJarTask.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2021 FabricMC
+ * Copyright (c) 2021-2025 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
@@ -26,6 +26,7 @@ package net.fabricmc.loom.task;
 
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 
 import javax.inject.Inject;
@@ -35,9 +36,6 @@ import org.gradle.api.provider.Property;
 import org.gradle.api.provider.Provider;
 import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.SourceSet;
-import org.gradle.api.tasks.TaskAction;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import net.fabricmc.loom.task.service.ClientEntriesService;
 import net.fabricmc.loom.task.service.SourceRemapperService;
@@ -56,8 +54,10 @@ public abstract class RemapSourcesJarTask extends AbstractRemapJarTask {
 		getSourcesRemapperServiceOptions().set(SourceRemapperService.createOptions(this));
 	}
 
-	@TaskAction
+	@Override
-	public void run() {
+	protected void copy() {
+		super.copy();
+
 		submitWork(RemapSourcesAction.class, params -> {
 			if (!params.namespacesMatch()) {
 				params.getSourcesRemapperServiceOptions().set(getSourcesRemapperServiceOptions());
@@ -75,15 +75,12 @@ public abstract class RemapSourcesJarTask extends AbstractRemapJarTask {
 	}
 
 	public abstract static class RemapSourcesAction extends AbstractRemapAction<RemapSourcesParams> {
-		private static final Logger LOGGER = LoggerFactory.getLogger(RemapSourcesAction.class);
-
 		public RemapSourcesAction() {
 			super();
 		}
 
 		@Override
-		public void execute() {
+		protected void execute(Path inputFile) throws IOException {
-			try {
 			if (!getParameters().namespacesMatch()) {
 				try (var serviceFactory = new ScopedServiceFactory()) {
 					SourceRemapperService sourceRemapperService = serviceFactory.get(getParameters().getSourcesRemapperServiceOptions());
@@ -95,15 +92,6 @@ public abstract class RemapSourcesJarTask extends AbstractRemapJarTask {
 
 			modifyJarManifest();
 			rewriteJar();
-			} catch (Exception e) {
-				try {
-					Files.deleteIfExists(outputFile);
-				} catch (IOException ex) {
-					LOGGER.error("Failed to delete output file", ex);
-				}
-
-				throw new RuntimeException("Failed to remap sources", e);
-			}
 		}
 	}
 }

src/main/java/net/fabricmc/loom/task/RemapTaskConfiguration.java

@@ -72,7 +72,7 @@ public abstract class RemapTaskConfiguration implements Runnable {
 
 		SyncTaskBuildService.register(getProject());
 
-		if (GradleUtils.getBooleanProperty(getProject(), Constants.Properties.DONT_REMAP)) {
+		if (extension.dontRemapOutputs()) {
 			extension.getUnmappedModCollection().from(getTasks().getByName(JavaPlugin.JAR_TASK_NAME));
 			return;
 		}

src/main/java/net/fabricmc/loom/task/prod/AbstractProductionRunTask.java

@@ -61,7 +61,6 @@ import net.fabricmc.loom.configuration.InstallerData;
 import net.fabricmc.loom.task.AbstractLoomTask;
 import net.fabricmc.loom.task.RemapTaskConfiguration;
 import net.fabricmc.loom.util.Constants;
-import net.fabricmc.loom.util.gradle.GradleUtils;
 
 /**
  * This is the base task for running the game in a "production" like environment. Using intermediary names, and not enabling development only features.
@@ -129,7 +128,7 @@ public abstract sealed class AbstractProductionRunTask extends AbstractLoomTask
 		getJavaLauncher().convention(getJavaToolchainService().launcherFor(defaultToolchain));
 		getRunDir().convention(getProject().getLayout().getProjectDirectory().dir("run"));
 
-		if (!GradleUtils.getBooleanProperty(getProject(), Constants.Properties.DONT_REMAP)) {
+		if (!getExtension().dontRemapOutputs()) {
 			getMods().from(getProject().getTasks().named(RemapTaskConfiguration.REMAP_JAR_TASK_NAME));
 		}
 

src/main/java/net/fabricmc/loom/task/service/MigrateMappingsService.java

@@ -32,6 +32,7 @@ import java.nio.file.Path;
 
 import org.cadixdev.lorenz.MappingSet;
 import org.cadixdev.mercury.Mercury;
+import org.cadixdev.mercury.mixin.MixinRemapper;
 import org.cadixdev.mercury.remapper.MercuryRemapper;
 import org.gradle.api.IllegalDependencyNotation;
 import org.gradle.api.JavaVersion;
@@ -57,6 +58,8 @@ import net.fabricmc.loom.api.mappings.layered.MappingsNamespace;
 import net.fabricmc.loom.configuration.providers.mappings.LayeredMappingSpecBuilderImpl;
 import net.fabricmc.loom.configuration.providers.mappings.LayeredMappingsFactory;
 import net.fabricmc.loom.configuration.providers.mappings.TinyMappingsService;
+import net.fabricmc.loom.util.DeletingFileVisitor;
+import net.fabricmc.loom.util.ExceptionUtil;
 import net.fabricmc.loom.util.service.Service;
 import net.fabricmc.loom.util.service.ServiceFactory;
 import net.fabricmc.loom.util.service.ServiceType;
@@ -123,7 +126,10 @@ public class MigrateMappingsService extends Service<MigrateMappingsService.Optio
 			throw new IllegalArgumentException("Could not find input directory: " + inputDir.toAbsolutePath());
 		}
 
-		Files.deleteIfExists(outputDir);
+		if (Files.exists(outputDir)) {
+			DeletingFileVisitor.deleteDirectory(outputDir);
+		}
+
 		Files.createDirectories(outputDir);
 
 		Mercury mercury = new Mercury();
@@ -139,6 +145,7 @@ public class MigrateMappingsService extends Service<MigrateMappingsService.Optio
 				MappingsNamespace.INTERMEDIARY.toString()
 		).read();
 
+		mercury.getProcessors().add(MixinRemapper.create(mappingSet));
 		mercury.getProcessors().add(MercuryRemapper.create(mappingSet));
 
 		for (File file : getOptions().getClasspath().getFiles()) {
@@ -151,7 +158,13 @@ public class MigrateMappingsService extends Service<MigrateMappingsService.Optio
 					outputDir
 			);
 		} catch (Exception e) {
-			LOGGER.warn("Could not remap fully!", e);
+			try {
+				DeletingFileVisitor.deleteDirectory(outputDir);
+			} catch (IOException ignored) {
+				// Nope
+			}
+
+			throw ExceptionUtil.createDescriptiveWrapper(RuntimeException::new, "Failed to migrate mappings", e);
 		}
 
 		// clean file descriptors

src/main/java/net/fabricmc/loom/task/service/SourceMappingsService.java

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2024 FabricMC
+ * Copyright (c) 2024-2025 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
@@ -34,8 +34,12 @@ import java.nio.file.Path;
 
 import org.gradle.api.Project;
 import org.gradle.api.file.ConfigurableFileCollection;
+import org.gradle.api.provider.Property;
 import org.gradle.api.provider.Provider;
+import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.Optional;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -61,17 +65,23 @@ public class SourceMappingsService extends Service<SourceMappingsService.Options
 	public interface Options extends Service.Options {
 		@InputFiles
 		ConfigurableFileCollection getMappings(); // Only a single file
+
+		@Input
+		@Optional
+		Property<String> getProcessorHash(); // the hash of the processors applied to the mappings
 	}
 
 	public static Provider<Options> create(Project project) {
-		final Path mappings = getMappings(project);
+		final Property<String> hash = project.getObjects().property(String.class);
+		final Path mappings = getMappings(project, hash);
 
 		return TYPE.create(project, options -> {
 			options.getMappings().from(project.file(mappings));
+			options.getProcessorHash().set(hash);
 		});
 	}
 
-	private static Path getMappings(Project project) {
+	private static Path getMappings(Project project, Property<String> hashProperty) {
 		final LoomGradleExtension extension = LoomGradleExtension.get(project);
 		final MinecraftJarProcessorManager jarProcessor = MinecraftJarProcessorManager.create(project);
 
@@ -80,8 +90,11 @@ public class SourceMappingsService extends Service<SourceMappingsService.Options
 			return extension.getMappingConfiguration().tinyMappings;
 		}
 
+		final String hash = jarProcessor.getSourceMappingsHash();
+		hashProperty.set(hash);
+
 		final Path dir = extension.getFiles().getProjectPersistentCache().toPath().resolve("source_mappings");
-		final Path path = dir.resolve(jarProcessor.getSourceMappingsHash() + ".tiny");
+		final Path path = dir.resolve(hash + ".tiny");
 
 		if (Files.exists(path) && !extension.refreshDeps()) {
 			LOGGER.debug("Using cached source mappings");
@@ -138,4 +151,8 @@ public class SourceMappingsService extends Service<SourceMappingsService.Options
 	public Path getMappingsFile() {
 		return getOptions().getMappings().getSingleFile().toPath();
 	}
+
+	public @Nullable String getProcessorHash() {
+		return getOptions().getProcessorHash().getOrNull();
+	}
 }

src/main/java/net/fabricmc/loom/util/Constants.java

@@ -169,6 +169,7 @@ public class Constants {
 
 	public static final class Properties {
 		public static final String DONT_REMAP = "fabric.loom.dontRemap";
+		public static final String DISABLE_OBFUSCATION = "fabric.loom.disableObfuscation";
 		public static final String DISABLE_REMAPPED_VARIANTS = "fabric.loom.disableRemappedVariants";
 		public static final String DISABLE_PROJECT_DEPENDENT_MODS = "fabric.loom.disableProjectDependentMods";
 		public static final String LIBRARY_PROCESSORS = "fabric.loom.libraryProcessors";

src/main/java/net/fabricmc/loom/util/fmj/gen/FabricModJsonV1Generator.java

@@ -165,7 +165,7 @@ public final class FabricModJsonV1Generator implements FabricModJsonGenerator<Fa
 		}
 
 		if (requirements.size() == 1) {
-			return new JsonPrimitive(dependency.getModId().get());
+			return new JsonPrimitive(requirements.getFirst());
 		}
 
 		JsonArray json = new JsonArray();

src/main/java/net/fabricmc/loom/util/gradle/SourceSetHelper.java

@@ -87,6 +87,10 @@ public final class SourceSetHelper {
 		return getSourceSetByName(SourceSet.MAIN_SOURCE_SET_NAME, project);
 	}
 
+	public static boolean isMainSourceSet(SourceSet sourceSet) {
+		return SourceSet.MAIN_SOURCE_SET_NAME.equals(sourceSet.getName());
+	}
+
 	public static SourceSet createSourceSet(String name, Project project) {
 		return getSourceSets(project).create(name);
 	}
@@ -303,4 +307,14 @@ public final class SourceSetHelper {
 
 		return null;
 	}
+
+	public static File getFirstSrcDir(SourceSet sourceSet) {
+		Iterator<File> iterator = sourceSet.getJava().getSrcDirs().iterator();
+
+		if (iterator.hasNext()) {
+			return iterator.next();
+		}
+
+		throw new IllegalStateException("SourceSet " + sourceSet.getName() + " has no source directories.");
+	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/MigrateMappingsTest.groovy

@@ -157,4 +157,91 @@ class MigrateMappingsTest extends Specification implements GradleProjectTestTrai
 		where:
 		version << STANDARD_TEST_VERSIONS
 	}
+
+	@Unroll
+	def "Migrate client mappings (gradle #version)"() {
+		setup:
+		def gradle = gradleProject(project: "minimalBase", version: version)
+		gradle.buildGradle << """
+            loom {
+                splitEnvironmentSourceSets()
+            }
+
+            dependencies {
+                minecraft 'com.mojang:minecraft:24w36a'
+                mappings 'net.fabricmc:yarn:24w36a+build.6:v2'
+            }
+            """.stripIndent()
+
+		def sourceFile = new File(gradle.projectDir, "src/client/java/example/Test.java")
+		sourceFile.parentFile.mkdirs()
+		sourceFile.text = """
+		package example;
+
+		import net.minecraft.predicate.entity.InputPredicate;
+
+		public class Test {
+			public static void main(String[] args) {
+			    InputPredicate cls = null;
+			}
+		}
+		"""
+
+		when:
+		def result = gradle.run(tasks: [
+			"migrateClientMappings",
+			"--mappings",
+			"net.minecraft:mappings:24w36a"
+		])
+		def remapped = new File(gradle.projectDir, "remappedClientSrc/example/Test.java").text
+
+		then:
+		result.task(":migrateClientMappings").outcome == SUCCESS
+		remapped.contains("import net.minecraft.advancements.critereon.InputPredicate;")
+
+		where:
+		version << STANDARD_TEST_VERSIONS
+	}
+
+	@Unroll
+	def "Override inputs (gradle #version)"() {
+		setup:
+		def gradle = gradleProject(project: "minimalBase", version: version)
+		gradle.buildGradle << """
+            dependencies {
+                minecraft 'com.mojang:minecraft:24w36a'
+                mappings 'net.fabricmc:yarn:24w36a+build.6:v2'
+            }
+            """.stripIndent()
+
+		def sourceFile = new File(gradle.projectDir, "src/main/java/example/Test.java")
+		sourceFile.parentFile.mkdirs()
+		sourceFile.text = """
+		package example;
+
+		import net.minecraft.predicate.entity.InputPredicate;
+
+		public class Test {
+			public static void main(String[] args) {
+			    InputPredicate cls = null;
+			}
+		}
+		"""
+
+		when:
+		def result = gradle.run(tasks: [
+			"migrateMappings",
+			"--mappings",
+			"net.minecraft:mappings:24w36a",
+			"--overrideInputsIHaveABackup"
+		])
+		def remapped = new File(gradle.projectDir, "src/main/java/example/Test.java").text
+
+		then:
+		result.task(":migrateMappings").outcome == SUCCESS
+		remapped.contains("import net.minecraft.advancements.critereon.InputPredicate;")
+
+		where:
+		version << STANDARD_TEST_VERSIONS
+	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/NotObfuscatedTest.groovy

@@ -0,0 +1,54 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2025 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 net.fabricmc.loom.test.integration
+
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
+
+import static net.fabricmc.loom.test.LoomTestConstants.PRE_RELEASE_GRADLE
+import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+
+class NotObfuscatedTest extends Specification implements GradleProjectTestTrait {
+	@Unroll
+	def "Not Obfuscated"() {
+		setup:
+		def gradle = gradleProject(project: "minimalBase", version: PRE_RELEASE_GRADLE)
+		gradle.buildGradle << '''
+				dependencies {
+					minecraft 'com.mojang:minecraft:1.21.10'
+                    api "net.fabricmc.fabric-api:fabric-api:0.134.1+1.21.10"
+                }
+		'''
+		gradle.getGradleProperties() << "fabric.loom.disableObfuscation=true"
+
+		when:
+		def result = gradle.run(task: "build")
+
+		then:
+		result.task(":build").outcome == SUCCESS
+	}
+}

src/test/groovy/net/fabricmc/loom/test/integration/RemapJarContentsTest.groovy

@@ -0,0 +1,62 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2025 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 net.fabricmc.loom.test.integration
+
+import java.util.jar.JarFile
+import java.util.jar.Manifest
+
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
+import net.fabricmc.loom.util.ZipUtils
+
+import static net.fabricmc.loom.test.LoomTestConstants.STANDARD_TEST_VERSIONS
+import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+
+class RemapJarContentsTest extends Specification implements GradleProjectTestTrait {
+	@Unroll
+	def "use jar apis on remapJar and remapSourcesJar (gradle #version)"() {
+		setup:
+		def gradle = gradleProject(project: "remapJarContents", version: version)
+
+		when:
+		def result = gradle.run(task: "build")
+
+		then:
+		result.task(":build").outcome == SUCCESS
+		ZipUtils.contains(gradle.getOutputFile('fabric-example-mod-1.0.0.jar').toPath(), 'test_file.txt')
+		ZipUtils.contains(gradle.getOutputFile('fabric-example-mod-1.0.0-sources.jar').toPath(), 'test_src_file.txt')
+		def manifest = readManifest(gradle.getOutputFile('fabric-example-mod-1.0.0.jar'))
+		manifest.mainAttributes.getValue('Hello-World') == 'test'
+
+		where:
+		version << STANDARD_TEST_VERSIONS
+	}
+
+	private static Manifest readManifest(File file) {
+		return new JarFile(file).withCloseable { it.manifest }
+	}
+}

src/test/groovy/net/fabricmc/loom/test/unit/SpecContextTest.groovy

@@ -39,8 +39,8 @@ import spock.lang.TempDir
 import net.fabricmc.loom.LoomGradleExtension
 import net.fabricmc.loom.api.RemapConfigurationSettings
 import net.fabricmc.loom.api.fmj.FabricModJsonV1Spec
-import net.fabricmc.loom.configuration.processors.SpecContextImpl
 import net.fabricmc.loom.configuration.processors.SpecContextProjectView
+import net.fabricmc.loom.configuration.processors.SpecContextRemappedImpl
 import net.fabricmc.loom.test.util.GradleTestUtil
 import net.fabricmc.loom.util.ZipUtils
 import net.fabricmc.loom.util.fmj.gen.FabricModJsonV1Generator
@@ -98,7 +98,7 @@ class SpecContextTest extends Specification {
 				)
 
 		when:
-		def specContext = SpecContextImpl.create(projectView)
+		def specContext = SpecContextRemappedImpl.create(projectView)
 
 		then:
 		specContext.modDependencies().size() == 0
@@ -117,7 +117,7 @@ class SpecContextTest extends Specification {
 				)
 
 		when:
-		def specContext = SpecContextImpl.create(projectView)
+		def specContext = SpecContextRemappedImpl.create(projectView)
 
 		then:
 		specContext.modDependencies().size() == 1
@@ -136,7 +136,7 @@ class SpecContextTest extends Specification {
 				)
 
 		when:
-		def specContext = SpecContextImpl.create(projectView)
+		def specContext = SpecContextRemappedImpl.create(projectView)
 
 		then:
 		specContext.modDependencies().size() == 1
@@ -155,7 +155,7 @@ class SpecContextTest extends Specification {
 				)
 
 		when:
-		def specContext = SpecContextImpl.create(projectView)
+		def specContext = SpecContextRemappedImpl.create(projectView)
 
 		then:
 		specContext.modDependencies().size() == 1
@@ -175,7 +175,7 @@ class SpecContextTest extends Specification {
 				)
 
 		when:
-		def specContext = SpecContextImpl.create(projectView)
+		def specContext = SpecContextRemappedImpl.create(projectView)
 
 		then:
 		specContext.modDependencies().size() == 1

src/test/groovy/net/fabricmc/loom/test/unit/fmj/FabricModJsonV1GeneratorTest.groovy

@@ -399,7 +399,7 @@ class FabricModJsonV1GeneratorTest extends Specification {
 		  "id": "examplemod",
 		  "version": "1.0.0",
 		  "depends": {
-		    "fabricloader": "fabricloader",
+		    "fabricloader": "\\u003e\\u003d0.14.0",
 		    "fabric-api": [
 		      "\\u003e\\u003d0.14.0",
 		      "\\u003c0.15.0"
@@ -592,23 +592,23 @@ class FabricModJsonV1GeneratorTest extends Specification {
 		  ],
 		  "accessWidener": "mymod.accesswidener",
 		  "depends": {
-		    "fabricloader": "fabricloader",
+		    "fabricloader": "\\u003e\\u003d0.14.0",
 		    "fabric-api": [
 		      "\\u003e\\u003d0.14.0",
 		      "\\u003c0.15.0"
 		    ]
 		  },
 		  "recommends": {
-		    "recommended-mod": "recommended-mod"
+		    "recommended-mod": "\\u003e\\u003d1.0.0"
 		  },
 		  "suggests": {
-		    "suggested-mod": "suggested-mod"
+		    "suggested-mod": "\\u003e\\u003d1.0.0"
 		  },
 		  "conflicts": {
-		    "conflicting-mod": "conflicting-mod"
+		    "conflicting-mod": "\\u003c1.0.0"
 		  },
 		  "breaks": {
-		    "broken-mod": "broken-mod"
+		    "broken-mod": "\\u003c1.0.0"
 		  },
 		  "name": "Example Mod",
 		  "description": "This is an example mod.",

src/test/resources/projects/remapJarContents/build.gradle

@@ -0,0 +1,91 @@
+plugins {
+	id 'fabric-loom'
+	id 'maven-publish'
+}
+
+version = loom.modVersion
+group = project.maven_group
+
+repositories {
+	// Add repositories to retrieve artifacts from in here.
+	// You should only use this when depending on other mods because
+	// Loom adds the essential maven repositories to download Minecraft and libraries from automatically.
+	// See https://docs.gradle.org/current/userguide/declaring_repositories.html
+	// for more information about repositories.
+}
+
+dependencies {
+	// To change the versions see the gradle.properties file
+	minecraft "com.mojang:minecraft:${project.minecraft_version}"
+	mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
+	modImplementation "net.fabricmc:fabric-loader:${project.loader_version}"
+
+	// Fabric API. This is technically optional, but you probably want it anyway.
+	modImplementation "net.fabricmc.fabric-api:fabric-api:${project.fabric_version}"
+
+	// PSA: Some older mods, compiled on Loom 0.2.1, might have outdated Maven POMs.
+	// You may need to force-disable transitiveness on them.
+}
+
+test {
+	enabled = false
+}
+
+base {
+	archivesName = project.archives_base_name
+}
+
+tasks.withType(JavaCompile).configureEach {
+	// ensure that the encoding is set to UTF-8, no matter what the system default is
+	// this fixes some edge cases with special characters not displaying correctly
+	// see http://yodaconditions.net/blog/fix-for-java-file-encoding-problems-with-gradle.html
+	// If Javadoc is generated, this must be specified in that task too.
+	it.options.encoding = "UTF-8"
+
+	// The Minecraft launcher currently installs Java 8 for users, so your mod probably wants to target Java 8 too
+	// JDK 9 introduced a new way of specifying this that will make sure no newer classes or methods are used.
+	// We'll use that if it's available, but otherwise we'll use the older option.
+	def targetVersion = 8
+	if (JavaVersion.current().isJava9Compatible()) {
+		it.options.release = targetVersion
+	}
+}
+
+java {
+	// Loom will automatically attach sourcesJar to a RemapSourcesJar task and to the "build" task
+	// if it is present.
+	// If you remove this line, sources will not be generated.
+	withSourcesJar()
+
+	sourceCompatibility = JavaVersion.VERSION_1_8
+	targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+// configure the maven publication
+publishing {
+	publications {
+		mavenJava(MavenPublication) {
+			from components.java
+		}
+	}
+
+	// See https://docs.gradle.org/current/userguide/publishing_maven.html for information on how to set up publishing.
+	repositories {
+		// Add repositories to publish to here.
+		// Notice: This block does NOT have the same function as the block in the top level.
+		// The repositories here will be used for publishing your artifact, not for
+		// retrieving dependencies.
+	}
+}
+
+remapJar {
+	from 'test_file.txt'
+
+	manifest {
+		attributes 'Hello-World': 'test'
+	}
+}
+
+remapSourcesJar {
+	from 'test_src_file.txt'
+}

src/test/resources/projects/remapJarContents/gradle.properties

@@ -0,0 +1,16 @@
+# Done to increase the memory available to gradle.
+org.gradle.jvmargs=-Xmx1G
+
+# Fabric Properties
+	# check these on https://fabricmc.net/use
+	minecraft_version=1.16.5
+	yarn_mappings=1.16.5+build.5
+	loader_version=0.11.2
+
+# Mod Properties
+	maven_group = com.example
+	archives_base_name = fabric-example-mod
+
+# Dependencies
+	# currently not on the main fabric site, check on the maven: https://maven.fabricmc.net/net/fabricmc/fabric-api/fabric-api
+	fabric_version=0.31.0+1.16

src/test/resources/projects/remapJarContents/settings.gradle

@@ -0,0 +1,2 @@
+rootProject.name = "fabric-example-mod"
+

src/test/resources/projects/remapJarContents/src/main/java/net/fabricmc/example/ExampleMod.java

@@ -0,0 +1,21 @@
+package net.fabricmc.example;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import net.fabricmc.api.ModInitializer;
+
+public class ExampleMod implements ModInitializer {
+	public static final Logger LOGGER = LogManager.getLogger("modid");
+
+	/**
+	 * @see net.fabricmc.example
+	 */
+	@Override
+	public void onInitialize() {
+		LOGGER.info("Hello simple Fabric mod!");
+		LOGGER.info("Hello World!");
+
+		net.minecraft.util.Identifier id = null;
+	}
+}

src/test/resources/projects/remapJarContents/src/main/java/net/fabricmc/example/mixin/ExampleMixin.java

@@ -0,0 +1,15 @@
+package net.fabricmc.example.mixin;
+
+import net.minecraft.client.gui.screen.TitleScreen;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(TitleScreen.class)
+public class ExampleMixin {
+	@Inject(at = @At("HEAD"), method = "init()V")
+	private void init(CallbackInfo info) {
+		System.out.println("This line is printed by an example mod mixin!");
+	}
+}

src/test/resources/projects/remapJarContents/src/main/resources/fabric.mod.json

@@ -0,0 +1,36 @@
+{
+  "schemaVersion": 1,
+  "id": "modid",
+  "version": "1.0.0",
+
+  "name": "Example Mod",
+  "description": "This is an example description! Tell everyone what your mod is about!",
+  "authors": [
+    "Me!"
+  ],
+  "contact": {
+    "homepage": "https://fabricmc.net/",
+    "sources": "https://github.com/FabricMC/fabric-example-mod"
+  },
+
+  "license": "CC0-1.0",
+
+  "environment": "*",
+  "entrypoints": {
+    "main": [
+      "net.fabricmc.example.ExampleMod"
+    ]
+  },
+  "mixins": [
+    "modid.mixins.json"
+  ],
+
+  "depends": {
+    "fabricloader": ">=0.7.4",
+    "fabric": "*",
+    "minecraft": "1.16.x"
+  },
+  "suggests": {
+    "another-mod": "*"
+  }
+}

src/test/resources/projects/remapJarContents/src/main/resources/modid.mixins.json

@@ -0,0 +1,14 @@
+{
+  "required": true,
+  "minVersion": "0.8",
+  "package": "net.fabricmc.example.mixin",
+  "compatibilityLevel": "JAVA_8",
+  "mixins": [
+  ],
+  "client": [
+    "ExampleMixin"
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}

src/test/resources/projects/remapJarContents/test_file.txt

@@ -0,0 +1 @@
+This file should end up inside the output file of remapJar.

src/test/resources/projects/remapJarContents/test_src_file.txt

@@ -0,0 +1 @@
+This file should end up inside the output file of remapSourcesJar.