Support Java 16 language features

[altrisi]

The issue occurred when trying to migrateMappings in a Fabric project (running Loom 0.8, 1.16.5 mod). May be an issue with some Java 16 feature, that class uses at least var. Assumed it's a Mercury issue since it's present in many positions in the stacktrace.

Stacktrace

``` java.lang.RuntimeException: Failed to process: path\to\altrisi\scarpetapptester\config\GSONRecordAdapter.java at org.cadixdev.mercury.Mercury.accept(Mercury.java:237) at org.cadixdev.mercury.Mercury$Requestor.acceptAST(Mercury.java:260) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:1068) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:662) at org.eclipse.jdt.core.dom.ASTParser.createASTs(ASTParser.java:1013) at org.cadixdev.mercury.Mercury.run(Mercury.java:212) at org.cadixdev.mercury.Mercury.rewrite(Mercury.java:167) at net.fabricmc.loom.task.MigrateMappingsTask.migrateMappings(MigrateMappingsTask.java:189) at net.fabricmc.loom.task.MigrateMappingsTask.doTask(MigrateMappingsTask.java:104) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:567) at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:58) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:51) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:29) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$2.run(ExecuteActionsTaskExecuter.java:498) at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29) at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:56) at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$run$1(DefaultBuildOperationExecutor.java:71) at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.runWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:45) at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:71) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:483) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:466) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$300(ExecuteActionsTaskExecuter.java:105) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.executeWithPreviousOutputFiles(ExecuteActionsTaskExecuter.java:270) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:248) at org.gradle.internal.execution.steps.ExecuteStep.executeInternal(ExecuteStep.java:83) at org.gradle.internal.execution.steps.ExecuteStep.access$000(ExecuteStep.java:37) at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:50) at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:47) at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200) at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62) at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76) at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54) at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76) at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:47) at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:37) at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:68) at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:38) at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:50) at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:36) at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:41) at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:74) at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:55) at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:51) at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:29) at org.gradle.internal.execution.steps.CaptureStateAfterExecutionStep.execute(CaptureStateAfterExecutionStep.java:54) at org.gradle.internal.execution.steps.CaptureStateAfterExecutionStep.execute(CaptureStateAfterExecutionStep.java:35) at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:60) at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:27) at org.gradle.internal.execution.steps.BuildCacheStep.executeWithoutCache(BuildCacheStep.java:174) at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:74) at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:45) at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:40) at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:29) at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:36) at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:22) at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:99) at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$0(SkipUpToDateStep.java:92) at java.base/java.util.Optional.map(Optional.java:260) at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:52) at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:36) at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:84) at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:41) at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:37) at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:27) at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:91) at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:49) at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:78) at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:49) at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:105) at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:50) at org.gradle.internal.execution.steps.SkipEmptyWorkStep.lambda$execute$2(SkipEmptyWorkStep.java:86) at java.base/java.util.Optional.orElseGet(Optional.java:364) at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:86) at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:32) at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:38) at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:43) at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:31) at org.gradle.internal.execution.steps.AssignWorkspaceStep.lambda$execute$0(AssignWorkspaceStep.java:40) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution$2.withWorkspace(ExecuteActionsTaskExecuter.java:283) at org.gradle.internal.execution.steps.AssignWorkspaceStep.execute(AssignWorkspaceStep.java:40) at org.gradle.internal.execution.steps.AssignWorkspaceStep.execute(AssignWorkspaceStep.java:30) at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:37) at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:27) at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:49) at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:35) at org.gradle.internal.execution.impl.DefaultExecutionEngine$1.execute(DefaultExecutionEngine.java:76) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:184) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:173) at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:109) at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46) at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51) at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57) at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56) at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52) at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200) at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75) at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153) at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68) at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62) at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76) at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54) at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52) at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:74) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:408) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:395) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:388) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:374) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.lambda$run$0(DefaultPlanExecutor.java:127) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:191) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:182) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:124) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56) at java.base/java.lang.Thread.run(Thread.java:831) Caused by: java.lang.IllegalArgumentException: Invalid identifier : >[Ljava< at org.eclipse.jdt.core.dom.SimpleName.setIdentifier(SimpleName.java:243) at org.eclipse.jdt.core.dom.AST.newSimpleName(AST.java:2597) at org.eclipse.jdt.core.dom.AST.newName(AST.java:2285) at org.cadixdev.mercury.remapper.RemapperVisitor.remapType(RemapperVisitor.java:124) at org.cadixdev.mercury.remapper.RemapperVisitor.visit(RemapperVisitor.java:178) at org.cadixdev.mercury.remapper.SimpleRemapperVisitor.visit(SimpleRemapperVisitor.java:183) at org.eclipse.jdt.core.dom.SimpleName.accept0(SimpleName.java:198) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.SimpleType.accept0(SimpleType.java:195) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.VariableDeclarationStatement.accept0(VariableDeclarationStatement.java:253) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.Block.accept0(Block.java:128) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.IfStatement.accept0(IfStatement.java:183) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.Block.accept0(Block.java:128) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.MethodDeclaration.accept0(MethodDeclaration.java:617) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.AnonymousClassDeclaration.accept0(AnonymousClassDeclaration.java:135) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.ClassInstanceCreation.accept0(ClassInstanceCreation.java:305) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.ReturnStatement.accept0(ReturnStatement.java:128) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.Block.accept0(Block.java:128) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChild(ASTNode.java:2975) at org.eclipse.jdt.core.dom.MethodDeclaration.accept0(MethodDeclaration.java:617) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.TypeDeclaration.accept0(TypeDeclaration.java:447) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2998) at org.eclipse.jdt.core.dom.CompilationUnit.accept0(CompilationUnit.java:258) at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2927) at org.cadixdev.mercury.remapper.MercuryRemapper.rewrite(MercuryRemapper.java:54) at org.cadixdev.mercury.SourceRewriter.process(SourceRewriter.java:20) at org.cadixdev.mercury.SourceContext.process(SourceContext.java:82) at org.cadixdev.mercury.RewriteContext.process(RewriteContext.java:106) at org.cadixdev.mercury.Mercury.accept(Mercury.java:235) ... 136 more :remapped project written to path\to\remappedSrc ```

Class where it fails

```java package altrisi.scarpetapptester.config; import java.io.IOException; import java.lang.reflect.Constructor; import java.util.HashMap; import com.google.gson.Gson; import com.google.gson.TypeAdapter; import com.google.gson.TypeAdapterFactory; import com.google.gson.reflect.TypeToken; import com.google.gson.stream.JsonReader; import com.google.gson.stream.JsonToken; import com.google.gson.stream.JsonWriter; class GSONRecordAdapter implements TypeAdapterFactory { @Override public TypeAdapter create(Gson gson, TypeToken type) { @SuppressWarnings("unchecked") Class clazz = (Class) type.getRawType(); if (!clazz.isRecord()) { return null; } TypeAdapter delegate = gson.getDelegateAdapter(this, type); return new TypeAdapter() { @Override public void write(JsonWriter out, T value) throws IOException { delegate.write(out, value); } @Override public T read(JsonReader reader) throws IOException { if (reader.peek() == JsonToken.NULL) { reader.nextNull(); return null; } else { var recordComponents = clazz.getRecordComponents(); var typeMap = new HashMap>(); for (int i = 0; i < recordComponents.length; i++) { typeMap.put(recordComponents[i].getName(), TypeToken.get(recordComponents[i].getGenericType())); } var argsMap = new HashMap(); reader.beginObject(); while (reader.hasNext()) { String name = reader.nextName(); argsMap.put(name, gson.getAdapter(typeMap.get(name)).read(reader)); } reader.endObject(); var argTypes = new Class[recordComponents.length]; var args = new Object[recordComponents.length]; for (int i = 0; i < recordComponents.length; i++) { argTypes[i] = recordComponents[i].getType(); args[i] = argsMap.get(recordComponents[i].getName()); } Constructor constructor; try { constructor = clazz.getDeclaredConstructor(argTypes); constructor.setAccessible(true); return constructor.newInstance(args); } catch (IllegalArgumentException | ReflectiveOperationException e) { throw new RuntimeException(e); } } } }; } } ```

Also (not sure if this is an issue with Mercury or not), after removing that class and running migrateMappings again, classes which declared records as nested classes got a failing import record; in their list of imports, and var was replaced with the actual type.

[jamierocks]

It's probably a consequence of the JDT being old in the published build - will update and publish a new Mercury version soon.

[jamierocks]

https://github.com/CadixDev/Mercury/commit/02771256f6926d5afe7ebb885edb2b172fd580a2 may well present a fix, unsure though.

[jamierocks]

Looks like we'll have to wait until JDT 3.26 - https://github.com/eclipse/eclipse.jdt.core/commit/fd6db01a1ee874ef9fe027d48fc549331ceea29a#diff-23943f685010f4e86bb88902ca769cd7ad6df4c88119e62dfbd50fcc1ec34474R21

[jpenilla]

Tested with Mercury 0.1.0 and manually bumping JDT to 3.27.0, records still don't remap properly/at all. References to records get remapped properly, however records themselves are not remapped. Top level records have the .java file renamed and nothing else, inner records fail to remap and seem to cause Mercury to give up on remapping that java file.

[quat1024]

Ran into this when using Loom's migrateMappings task to convert a 1.17 mod that used records in its source code from yarn to mojang names. No members inside the record get remapped; sometimes it would just delete all the imports from the file and carry on.

Since I control the mod source, the solution was to use intellij's "convert record to class" intention on all the records, run the Gradle task, then convert them all back