Merge remote-tracking branch 'FabricMC/dev/0.9' into dev/0.9

# Conflicts:
#	build.gradle
#	src/main/java/net/fabricmc/loom/LoomGradleExtension.java
#	src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java
#	src/main/java/net/fabricmc/loom/build/JarRemapper.java
#	src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
#	src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
#	src/main/java/net/fabricmc/loom/configuration/providers/mappings/GradleMappingContext.java
#	src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java
#	src/main/java/net/fabricmc/loom/task/AbstractLoomTask.java
#	src/main/java/net/fabricmc/loom/task/AbstractRunTask.java
#	src/main/java/net/fabricmc/loom/task/LoomTasks.java
#	src/main/java/net/fabricmc/loom/util/Constants.java
#	src/main/java/net/fabricmc/loom/util/SourceRemapper.java
#	src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingSpecBuilderTest.groovy
#	src/test/resources/projects/kotlin/build.gradle.kts

15 files changed, 158 insertions, 42 deletions

diff --git a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
index 42d6e0fd..e6589da5 100644
--- a/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
+++ b/src/main/java/net/fabricmc/loom/configuration/CompileConfiguration.java
@@ -29,7 +29,6 @@ import org.gradle.api.artifacts.ConfigurationContainer;
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginConvention;
 import org.gradle.api.tasks.SourceSet;
-import org.gradle.api.tasks.compile.JavaCompile;
 import org.gradle.api.tasks.javadoc.Javadoc;
 import org.gradle.jvm.tasks.Jar;
 
@@ -147,11 +146,6 @@ public final class CompileConfiguration {
 		Javadoc javadoc = (Javadoc) p.getTasks().getByName(JavaPlugin.JAVADOC_TASK_NAME);
 		javadoc.setClasspath(main.getOutput().plus(main.getCompileClasspath()));
 
-		p.getTasks().withType(JavaCompile.class).configureEach(compile -> {
-			// Fork the java compiler to ensure that it does not keep any files open.
-			compile.getOptions().setFork(true);
-		});
-
 		p.afterEvaluate(project -> {
 			LoomGradleExtension extension = LoomGradleExtension.get(project);
 
@@ -186,9 +180,10 @@ public final class CompileConfiguration {
 
 			SetupIntelijRunConfigs.setup(project);
 			GenVsCodeProjectTask.generate(project);
+			extension.getRemapArchives().finalizeValue();
 
 			// Enables the default mod remapper
-			if (extension.isRemapMod()) {
+			if (extension.getRemapArchives().get()) {
 				RemapConfiguration.setupDefaultRemap(project);
 			} else {
 				Jar jarTask = (Jar) project.getTasks().getByName("jar");
@@ -201,7 +196,7 @@ public final class CompileConfiguration {
 			System.setProperty("log4j.skipJansi", "true");
 
 			project.getLogger().info("Configuring compiler arguments for Java");
-			MixinApExtension mixinApExtension = LoomGradleExtension.get(project).getMixinApExtension();
+			MixinApExtension mixinApExtension = LoomGradleExtension.get(project).getMixin();
 			mixinApExtension.init();
 
 			new JavaApInvoker(project).configureMixin();
diff --git a/src/main/java/net/fabricmc/loom/configuration/LoomDependencyManager.java b/src/main/java/net/fabricmc/loom/configuration/LoomDependencyManager.java
index b0568731..b14d2678 100644
--- a/src/main/java/net/fabricmc/loom/configuration/LoomDependencyManager.java
+++ b/src/main/java/net/fabricmc/loom/configuration/LoomDependencyManager.java
@@ -25,6 +25,7 @@
 package net.fabricmc.loom.configuration;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -170,7 +171,15 @@ public class LoomDependencyManager {
 
 		ModCompileRemapper.remapDependencies(project, mappingsKey, extension, sourceRemapper);
 
-		sourceRemapper.remapAll();
+		long start = System.currentTimeMillis();
+
+		try {
+			sourceRemapper.remapAll();
+		} catch (IOException exception) {
+			throw new RuntimeException("Failed to remap mod sources", exception);
+		}
+
+		project.getLogger().info("Source remapping took: %dms".formatted(System.currentTimeMillis() - start));
 
 		for (Runnable runnable : afterTasks) {
 			runnable.run();
diff --git a/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java b/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
index f8d45018..6afcf2c1 100644
--- a/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
+++ b/src/main/java/net/fabricmc/loom/configuration/RemapConfiguration.java
@@ -105,7 +105,7 @@ public class RemapConfiguration {
 		// TODO what is this for?
 		Task parentTask = project.getTasks().getByName("build");
 
-		if (extension.isShareCaches()) {
+		if (extension.getShareRemapCaches().get()) {
 			Project rootProject = project.getRootProject();
 
 			if (extension.isRootProject()) {
@@ -116,7 +116,6 @@ public class RemapConfiguration {
 
 				rootProject.getTasks().register(remapAllSourcesTaskName, RemapAllSourcesTask.class, task -> {
 					task.sourceRemapper = sourceRemapper;
-					task.doLast(t -> sourceRemapper.remapAll());
 				});
 
 				parentTask = rootProject.getTasks().getByName(remapAllSourcesTaskName);
@@ -165,7 +164,7 @@ public class RemapConfiguration {
 				});
 			}
 
-			if (extension.isShareCaches()) {
+			if (extension.getShareRemapCaches().get()) {
 				remapSourcesJarTask.setSourceRemapper(remapper);
 			}
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java b/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
index ef2f37e1..cecf4d34 100644
--- a/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
+++ b/src/main/java/net/fabricmc/loom/configuration/accesswidener/AccessWidenerJarProcessor.java
@@ -71,16 +71,22 @@ public class AccessWidenerJarProcessor implements JarProcessor {
 	}
 
 	@Override
+	public String getId() {
+		return "loom:access_widener";
+	}
+
+	@Override
 	public void setup() {
 		LoomGradleExtension loomGradleExtension = LoomGradleExtension.get(project);
+		File awPath = loomGradleExtension.getAccessWidenerPath().get().getAsFile();
 
-		if (!loomGradleExtension.getAccessWidener().exists()) {
-			throw new RuntimeException("Could not find access widener file @ " + loomGradleExtension.getAccessWidener().getAbsolutePath());
+		if (!awPath.exists()) {
+			throw new RuntimeException("Could not find access widener file @ " + awPath.getAbsolutePath());
 		}
 
-		inputHash = Checksum.sha256(loomGradleExtension.getAccessWidener());
+		inputHash = Checksum.sha256(awPath);
 
-		try (BufferedReader reader = new BufferedReader(new FileReader(loomGradleExtension.getAccessWidener()))) {
+		try (BufferedReader reader = new BufferedReader(new FileReader(awPath))) {
 			accessWidenerReader.read(reader);
 		} catch (IOException e) {
 			throw new RuntimeException("Failed to read project access widener file");
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 a9335764..8c60619f 100644
--- a/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
+++ b/src/main/java/net/fabricmc/loom/configuration/ide/RunConfig.java
@@ -52,6 +52,7 @@ import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 
 import net.fabricmc.loom.LoomGradleExtension;
+import net.fabricmc.loom.configuration.InstallerData;
 import net.fabricmc.loom.util.OperatingSystem;
 
 public class RunConfig {
@@ -269,7 +270,13 @@ public class RunConfig {
 	}
 
 	private static String getMainClass(String side, LoomGradleExtension extension, String defaultMainClass) {
-		JsonObject installerJson = extension.getInstallerData() == null ? null : extension.getInstallerData().installerJson();
+		InstallerData installerData = extension.getInstallerData() == null ? null : extension.getInstallerData();
+
+		if (installerData == null) {
+			return defaultMainClass;
+		}
+
+		JsonObject installerJson = installerData.installerJson();
 
 		if (installerJson != null && installerJson.has("mainClass")) {
 			JsonElement mainClassJson = installerJson.get("mainClass");
diff --git a/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessor.java b/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessor.java
index 33cde23b..71f9a6bf 100644
--- a/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessor.java
+++ b/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessor.java
@@ -27,6 +27,18 @@ package net.fabricmc.loom.configuration.processors;
 import java.io.File;
 
 public interface JarProcessor {
+	/**
+	 * Returns a unique ID for this jar processor, containing all configuration details.
+	 *
+	 * <p>If the jar processor implementation class supports creating multiple jar processors with different effects,
+	 * the needed configuration should also be included in this ID. Example: {@code path.to.MyJarProcessor#someOption}.
+	 *
+	 * @return the ID of this jar processor
+	 */
+	default String getId() {
+		return getClass().getName();
+	}
+
 	void setup();
 
 	/**
diff --git a/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessorManager.java b/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessorManager.java
index 9ee6864d..4c36c40d 100644
--- a/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessorManager.java
+++ b/src/main/java/net/fabricmc/loom/configuration/processors/JarProcessorManager.java
@@ -25,9 +25,27 @@
 package net.fabricmc.loom.configuration.processors;
 
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
+import java.util.jar.Attributes;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+import java.util.stream.Collectors;
+import java.util.zip.ZipEntry;
+
+import com.google.common.hash.Hashing;
+import com.google.common.io.CharSource;
+import org.zeroturnaround.zip.ZipUtil;
+import org.zeroturnaround.zip.transform.StreamZipEntryTransformer;
+import org.zeroturnaround.zip.transform.ZipEntryTransformerEntry;
 
 public class JarProcessorManager {
+	private static final String MANIFEST_PATH = "META-INF/MANIFEST.MF";
+	private static final String JAR_PROCESSOR_HASH_ATTRIBUTE = "Loom-Jar-Processor-Hash";
 	private final List<JarProcessor> jarProcessors;
 
 	public JarProcessorManager(List<JarProcessor> jarProcessors) {
@@ -47,13 +65,56 @@ public class JarProcessorManager {
 			return true;
 		}
 
+		String jarProcessorHash = getJarProcessorHash();
+
+		try (JarFile jar = new JarFile(file)) {
+			Attributes attributes = jar.getManifest().getMainAttributes();
+
+			if (!jarProcessorHash.equals(attributes.getValue(JAR_PROCESSOR_HASH_ATTRIBUTE))) {
+				return true;
+			}
+		} catch (IOException e) {
+			throw new UncheckedIOException("Could not check jar manifest of " + file, e);
+		}
+
 		return jarProcessors.stream().anyMatch(jarProcessor -> jarProcessor.isInvalid(file));
 	}
 
+	private String getJarProcessorHash() {
+		String jarProcessorIds = jarProcessors.stream()
+				.map(JarProcessor::getId)
+				.sorted()
+				.collect(Collectors.joining(";"));
+
+		try {
+			return CharSource.wrap(jarProcessorIds)
+					.asByteSource(StandardCharsets.UTF_8)
+					.hash(Hashing.sha256())
+					.toString();
+		} catch (IOException e) {
+			throw new UncheckedIOException("Could not hash jar processor IDs", e);
+		}
+	}
+
 	public void process(File file) {
 		for (JarProcessor jarProcessor : jarProcessors) {
 			jarProcessor.process(file);
 		}
+
+		boolean manifestTransformed = ZipUtil.transformEntries(file, new ZipEntryTransformerEntry[] {
+				new ZipEntryTransformerEntry(MANIFEST_PATH, new StreamZipEntryTransformer() {
+					@Override
+					protected void transform(ZipEntry zipEntry, InputStream in, OutputStream out) throws IOException {
+						Manifest manifest = new Manifest(in);
+						manifest.getMainAttributes().putValue(JAR_PROCESSOR_HASH_ATTRIBUTE, getJarProcessorHash());
+						manifest.write(out);
+					}
+				})
+		});
+
+		if (!manifestTransformed) {
+			throw new RuntimeException("Could not add data to jar manifest in " + file);
+		}
 	}
 
 	public <T extends JarProcessor> T getByType(Class<T> tClass) {
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProviderImpl.java b/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProviderImpl.java
index fa6e5703..2ac31e06 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProviderImpl.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/MinecraftProviderImpl.java
@@ -135,7 +135,7 @@ public class MinecraftProviderImpl extends DependencyProvider implements Minecra
 	}
 
 	private void downloadMcJson(boolean offline) throws IOException {
-		if (getExtension().isShareCaches() && !getExtension().isRootProject() && versionManifestJson.exists() && !isRefreshDeps()) {
+		if (getExtension().getShareRemapCaches().get() && !getExtension().isRootProject() && versionManifestJson.exists() && !isRefreshDeps()) {
 			return;
 		}
 
@@ -159,10 +159,10 @@ public class MinecraftProviderImpl extends DependencyProvider implements Minecra
 
 		Optional<ManifestVersion.Versions> optionalVersion = Optional.empty();
 
-		if (getExtension().getCustomManifest() != null) {
+		if (getExtension().getCustomMinecraftManifest().isPresent()) {
 			ManifestVersion.Versions customVersion = new ManifestVersion.Versions();
 			customVersion.id = minecraftVersion;
-			customVersion.url = getExtension().getCustomManifest();
+			customVersion.url = getExtension().getCustomMinecraftManifest().get();
 			optionalVersion = Optional.of(customVersion);
 			getProject().getLogger().lifecycle("Using custom minecraft manifest");
 		}
@@ -226,7 +226,7 @@ public class MinecraftProviderImpl extends DependencyProvider implements Minecra
 	}
 
 	private boolean hasRecentValidManifest() throws IOException {
-		if (getExtension().getCustomManifest() != null) {
+		if (getExtension().getCustomMinecraftManifest().isPresent()) {
 			return false;
 		}
 
@@ -247,7 +247,7 @@ public class MinecraftProviderImpl extends DependencyProvider implements Minecra
 	}
 
 	private void downloadJars(Logger logger) throws IOException {
-		if (getExtension().isShareCaches() && !getExtension().isRootProject() && minecraftClientJar.exists() && minecraftServerJar.exists() && !isRefreshDeps()) {
+		if (getExtension().getShareRemapCaches().get() && !getExtension().isRootProject() && minecraftClientJar.exists() && minecraftServerJar.exists() && !isRefreshDeps()) {
 			return;
 		}
 
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 db478671..ced88424 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
@@ -25,8 +25,9 @@
 package net.fabricmc.loom.configuration.providers.mappings;
 
 import java.io.File;
-import java.util.function.Supplier;
+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;
@@ -37,12 +38,11 @@ import net.fabricmc.loom.configuration.providers.MinecraftProvider;
 public class GradleMappingContext implements MappingContext {
 	private final Project project;
 	private final LoomGradleExtension extension;
-	private final Supplier<String> workingDirName;
+	private File workingDir;
 
-	public GradleMappingContext(Project project, Supplier<String> workingDirName) {
+	public GradleMappingContext(Project project) {
 		this.project = project;
 		this.extension = LoomGradleExtension.get(project);
-		this.workingDirName = workingDirName;
 	}
 
 	@Override
@@ -62,10 +62,28 @@ public class GradleMappingContext implements MappingContext {
 	}
 
 	@Override
+	public File workingDirectory() {
+		if (workingDir == null) {
+			workingDir = new File(mappingsProvider().getMappingsDir().toFile(), "layered/" + minecraftProvider().minecraftVersion());
+
+			if (workingDir.exists()) {
+				try {
+					FileUtils.deleteDirectory(workingDir);
+				} catch (IOException e) {
+					getLogger().warn("Failed to cleanup layered mappings working directory: {}", e.getMessage());
+				}
+			}
+		}
+
+		return workingDir;
+	}
+
+	@Override
 	public File workingDirectory(String name) {
-		File tempDir = new File(mappingsProvider().getMappingsDir().toFile(), workingDirName.get());
-		tempDir.mkdirs();
-		return new File(tempDir, name);
+		File file = new File(workingDirectory(), name);
+		file.mkdirs();
+
+		return file;
 	}
 
 	@Override
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingSpec.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingSpec.java
index 2e47af39..f42a3289 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingSpec.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/LayeredMappingSpec.java
@@ -27,8 +27,8 @@ package net.fabricmc.loom.configuration.providers.mappings;
 import java.util.List;
 
 public record LayeredMappingSpec(List<MappingsSpec<?>> layers) {
-	public String getVersion() {
+	public String getVersion(MappingContext context) {
 		// TODO something better?
-		return "layered+hash.%d".formatted(Math.abs(hashCode()));
+		return "layered+hash.%d.minecraft.%s".formatted(Math.abs(hashCode()), context.minecraftVersion());
 	}
 }
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 1b5d673f..b253a114 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
@@ -54,17 +54,16 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 
 	private final MappingContext mappingContext;
 	private final LayeredMappingSpec layeredMappingSpec;
-	private final String version;
+	private String version = null;
 
-	public LayeredMappingsDependency(MappingContext mappingContext, LayeredMappingSpec layeredMappingSpec, String version) {
+	public LayeredMappingsDependency(MappingContext mappingContext, LayeredMappingSpec layeredMappingSpec) {
 		this.mappingContext = mappingContext;
 		this.layeredMappingSpec = layeredMappingSpec;
-		this.version = version;
 	}
 
 	@Override
 	public Set<File> resolve() {
-		Path mappingsDir = mappingContext.mappingsProvider().getMappingsDir();
+		Path mappingsDir = mappingContext.workingDirectory().toPath();
 		Path mappingsFile = mappingsDir.resolve(String.format("%s.%s-%s.tiny", GROUP, MODULE, getVersion()));
 
 		if (!Files.exists(mappingsFile) || LoomGradlePlugin.refreshDeps) {
@@ -115,6 +114,10 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 
 	@Override
 	public String getVersion() {
+		if (version == null) {
+			version = layeredMappingSpec.getVersion(mappingContext);
+		}
+
 		return version;
 	}
 
@@ -129,7 +132,7 @@ public class LayeredMappingsDependency implements SelfResolvingDependency {
 
 	@Override
 	public Dependency copy() {
-		return new LayeredMappingsDependency(mappingContext, layeredMappingSpec, version);
+		return new LayeredMappingsDependency(mappingContext, layeredMappingSpec);
 	}
 
 	@Override
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingContext.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingContext.java
index 3fbfb655..0ccd61ea 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingContext.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/MappingContext.java
@@ -41,6 +41,8 @@ public interface MappingContext {
 		return minecraftProvider().minecraftVersion();
 	}
 
+	File workingDirectory();
+
 	/**
 	 * Creates a temporary working dir to be used to store working files.
 	 */
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 1de460e8..f15f6eca 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
@@ -277,11 +277,13 @@ public class MappingsProviderImpl extends DependencyProvider implements Mappings
 
 		LoomGradleExtension extension = getExtension();
 
-		if (extension.getAccessWidener() != null) {
-			extension.addJarProcessor(new AccessWidenerJarProcessor(getProject()));
+		if (extension.getAccessWidenerPath().isPresent()) {
+			extension.getGameJarProcessors().add(new AccessWidenerJarProcessor(getProject()));
 		}
 
-		JarProcessorManager processorManager = new JarProcessorManager(extension.getJarProcessors());
+		extension.getAccessWidenerPath().finalizeValue();
+		extension.getGameJarProcessors().finalizeValue();
+		JarProcessorManager processorManager = new JarProcessorManager(extension.getGameJarProcessors().get());
 		extension.setJarProcessorManager(processorManager);
 		processorManager.setupProcessors();
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingLayer.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingLayer.java
index 251ff986..4b4d407b 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingLayer.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingLayer.java
@@ -44,15 +44,16 @@ import net.fabricmc.mappingio.MappingVisitor;
 import net.fabricmc.mappingio.adapter.MappingSourceNsSwitch;
 import net.fabricmc.mappingio.format.ProGuardReader;
 
-public record MojangMappingLayer(MinecraftVersionMeta.Download clientDownload,
+public record MojangMappingLayer(String minecraftVersion,
+									MinecraftVersionMeta.Download clientDownload,
 									MinecraftVersionMeta.Download serverDownload,
 									File workingDir,
 									Logger logger,
 									MojangMappingsSpec.SilenceLicenseOption silenceLicense) implements MappingLayer {
 	@Override
 	public void visit(MappingVisitor mappingVisitor) throws IOException {
-		var clientMappings = new File(workingDir(), "client.txt");
-		var serverMappings = new File(workingDir(), "server.txt");
+		var clientMappings = new File(workingDir(), "%s.client.txt".formatted(minecraftVersion));
+		var serverMappings = new File(workingDir(), "%s.server.txt".formatted(minecraftVersion));
 
 		download(clientMappings, serverMappings);
 
diff --git a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingsSpec.java b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingsSpec.java
index 67f22460..f304530f 100644
--- a/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingsSpec.java
+++ b/src/main/java/net/fabricmc/loom/configuration/providers/mappings/mojmap/MojangMappingsSpec.java
@@ -78,6 +78,7 @@ public record MojangMappingsSpec(SilenceLicenseOption silenceLicense) implements
 		}
 
 		return new MojangMappingLayer(
+				context.minecraftVersion(),
 				versionInfo.download(MANIFEST_CLIENT_MAPPINGS),
 				versionInfo.download(MANIFEST_SERVER_MAPPINGS),
 				context.workingDirectory("mojang"),