java.lang.AssertionError: isSameType UNKNOWN
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitType(Types.java:1121)
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitType(Types.java:1093)
   at com.sun.tools.javac.code.Type.accept(Type.java:189)
   at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4498)
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitClassType(Types.java:1141)
   at com.sun.tools.javac.code.Types$SameTypeVisitor.visitClassType(Types.java:1093)
   at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:778)
   at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4498)
   at com.sun.tools.javac.code.Types.isSameType(Types.java:1085)
   at com.sun.tools.javac.code.Types.isSameTypes(Types.java:1053)
   at com.sun.tools.javac.code.Types.isSameTypes(Types.java:1049)
   at com.sun.tools.javac.comp.Attr.checkLambdaCompatible(Attr.java:2693)
   at com.sun.tools.javac.comp.Attr.visitLambda(Attr.java:2496)
   at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1630)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:614)
   at com.sun.tools.javac.comp.Attr.visitVarDef(Attr.java:1081)
   at com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:858)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:572)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:641)
   at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4560)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4462)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4390)
   at com.sun.tools.javac.comp.Attr.attrib(Attr.java:4365)
   at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1311)
   at com.sun.tools.javac.api.JavacTaskImpl$1.process(JavacTaskImpl.java:473)
   at com.sun.tools.javac.api.JavacTaskImpl$Filter.run(JavacTaskImpl.java:623)
   at com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:476)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:272)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:251)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:300)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2749)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$400(RepositoryUpdater.java:2153)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2635)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2633)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:546)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2633)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3286)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3252)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$3.run(RepositoryUpdater.java:2126)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:295)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2122)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2103)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.access$1100(RepositoryUpdater.java:156)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.scanFiles(RepositoryUpdater.java:3252)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$FileListWork.getDone(RepositoryUpdater.java:3771)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3406)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:6170)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4300(RepositoryUpdater.java:5817)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3$1.run(RepositoryUpdater.java:6088)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:295)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:106)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:6084)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:6080)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:6080)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1425)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:59)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:294)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2038)