java.lang.AssertionError: isSameType UNKNOWN
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitType(Types.java:1004)
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitType(Types.java:976)
   at com.sun.tools.javac.code.Type.accept(Type.java:184)
   at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4260)
   at com.sun.tools.javac.code.Types.isSameType(Types.java:968)
   at com.sun.tools.javac.code.Types.isSameType(Types.java:965)
   at com.sun.tools.javac.comp.MemberEnter.isSameAPType(MemberEnter.java:601)
   at com.sun.tools.javac.comp.MemberEnter.isSameMethod(MemberEnter.java:620)
   at com.sun.tools.javac.comp.MemberEnter.visitMethodDef(MemberEnter.java:667)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:776)
   at com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:442)
   at com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:454)
   at com.sun.tools.javac.comp.MemberEnter.finishClass(MemberEnter.java:465)
   at com.sun.tools.javac.comp.MemberEnter.finish(MemberEnter.java:1498)
   at com.sun.tools.javac.comp.MemberEnter.complete(MemberEnter.java:1315)
   at com.sun.tools.javac.code.Symbol.complete(Symbol.java:437)
   at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:901)
   at com.sun.tools.javac.code.Symbol$ClassSymbol.flags(Symbol.java:832)
   at com.sun.tools.javac.code.Symbol.getModifiers(Symbol.java:460)
   at org.netbeans.modules.java.source.indexing.CheckSums.getExtendedModifiers(CheckSums.java:181)
   at org.netbeans.modules.java.source.indexing.CheckSums.computeCheckSum(CheckSums.java:146)
   at org.netbeans.modules.java.source.indexing.CheckSums.checkAndSet(CheckSums.java:99)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:299)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:246)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:282)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2612)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$1400(RepositoryUpdater.java:2077)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2502)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2500)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:544)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2500)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:5201)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:4910)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:4615)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$InitialRootsWork.getDone(RepositoryUpdater.java:5296)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3205)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:5643)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4900(RepositoryUpdater.java:5309)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3$1.run(RepositoryUpdater.java:5568)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:96)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5564)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5560)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:74)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:5560)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
   at java.util.concurrent.FutureTask.run(FutureTask.java:166)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)