A DESCRIPTION OF THE PROBLEM :
Compile the following code:
interface I0<T, T, K> {
}
A crash occurs: 
java.lang.NullPointerException
	at com.sun.tools.javac.comp.MemberEnter.baseEnv(MemberEnter.java:1400)
	at com.sun.tools.javac.comp.MemberEnter.complete(MemberEnter.java:1058)
	at com.sun.tools.javac.code.Symbol.complete(Symbol.java:574)
	at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:1037)
	at com.sun.tools.javac.code.Symbol$ClassSymbol.flags(Symbol.java:973)
	at com.sun.tools.javac.code.Symbol$ClassSymbol.getKind(Symbol.java:1101)
	at com.sun.tools.javac.code.Kinds.kindName(Kinds.java:162)
	at com.sun.tools.javac.comp.Check.duplicateError(Check.java:329)
	at com.sun.tools.javac.comp.Check.checkUnique(Check.java:3383)
	at com.sun.tools.javac.comp.Enter.visitTypeParameter(Enter.java:454)
	at com.sun.tools.javac.tree.JCTree$JCTypeParameter.accept(JCTree.java:2224)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:258)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:272)
	at com.sun.tools.javac.comp.Enter.visitClassDef(Enter.java:418)
	at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:693)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:258)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:272)
	at com.sun.tools.javac.comp.Enter.visitTopLevel(Enter.java:334)
	at com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:518)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:258)
	at com.sun.tools.javac.comp.Enter.classEnter(Enter.java:272)
	at com.sun.tools.javac.comp.Enter.complete(Enter.java:486)
	at com.sun.tools.javac.comp.Enter.main(Enter.java:471)
	at com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:982)
	at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:857)
	at com.sun.tools.javac.main.Main.compile(Main.java:523)
	at com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:129)
	at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:138)
	at org.gradle.internal.compiler.java.IncrementalCompileTask.call(IncrementalCompileTask.java:92)
	at org.gradle.api.internal.tasks.compile.AnnotationProcessingCompileTask.call(AnnotationProcessingCompileTask.java:94)
	at org.gradle.api.internal.tasks.compile.ResourceCleaningCompilationTask.call(ResourceCleaningCompilationTask.java:57)
	at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:76)
	at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:46)
	at org.gradle.api.internal.tasks.compile.daemon.AbstractIsolatedCompilerWorkerExecutor$CompilerWorkAction.execute(AbstractIsolatedCompilerWorkerExecutor.java:78)
	at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:63)
	at org.gradle.workers.internal.AbstractClassLoaderWorker$1.create(AbstractClassLoaderWorker.java:54)
	at org.gradle.workers.internal.AbstractClassLoaderWorker$1.create(AbstractClassLoaderWorker.java:48)
	at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:100)
	at org.gradle.workers.internal.AbstractClassLoaderWorker.executeInClassLoader(AbstractClassLoaderWorker.java:48)
	at org.gradle.workers.internal.FlatClassLoaderWorker.run(FlatClassLoaderWorker.java:32)
	at org.gradle.workers.internal.FlatClassLoaderWorker.run(FlatClassLoaderWorker.java:22)
	at org.gradle.workers.internal.WorkerDaemonServer.run(WorkerDaemonServer.java:103)
	at org.gradle.workers.internal.WorkerDaemonServer.run(WorkerDaemonServer.java:72)
	at org.gradle.process.internal.worker.request.WorkerAction$1.call(WorkerAction.java:152)
	at org.gradle.process.internal.worker.child.WorkerLogEventListener.withWorkerLoggingProtocol(WorkerLogEventListener.java:41)
	at org.gradle.process.internal.worker.request.WorkerAction.lambda$run$1(WorkerAction.java:149)
	at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
	at org.gradle.process.internal.worker.request.WorkerAction.run(WorkerAction.java:141)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
	at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
	at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)