ADDITIONAL SYSTEM INFORMATION :
OSX 10.13.4, compiling under gradle, same error with gradle parallel enabled and disabled.
gradle itself running with 1g - 2g memory,

A DESCRIPTION OF THE PROBLEM :
The exception first happened on 162, but reproduces identically on the latest release, 172.
Did not happen before my code changes a few hours back.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
gradle clean followed by gradle all

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
compile succeeds or fails due to code problems
ACTUAL -
compiler fails due to internal compiler assertion fails:
> Task :Src:Libraries:PropertyWidget:compileJava FAILED
An exception has occurred in the compiler (1.8.0_172). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.AssertionError
at com.sun.tools.javac.util.Assert.error(Assert.java:126)
at com.sun.tools.javac.util.Assert.check(Assert.java:45)
at com.sun.tools.javac.code.Types.functionalInterfaceBridges(Types.java:659)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$TranslationContext.<init>(LambdaToMethod.java:1770)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$LambdaTranslationContext.<init>(LambdaToMethod.java:1853)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.analyzeLambda(LambdaToMethod.java:1337)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitLambda(LambdaToMethod.java:1322)
at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1624)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitApply(TreeTranslator.java:275)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitApply(LambdaToMethod.java:1208)
at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1465)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.visitExec(TreeTranslator.java:245)
at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1296)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitBlock(TreeTranslator.java:162)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitBlock(LambdaToMethod.java:1231)
at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:909)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.visitMethodDef(TreeTranslator.java:145)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitMethodDef(LambdaToMethod.java:1361)
at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:778)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitClassDef(TreeTranslator.java:134)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitClassDef(LambdaToMethod.java:1270)
at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:693)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.analyzeAndPreprocessClass(LambdaToMethod.java:1197)
at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.access$300(LambdaToMethod.java:1148)
at com.sun.tools.javac.comp.LambdaToMethod.visitClassDef(LambdaToMethod.java:232)
at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:693)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.LambdaToMethod.translate(LambdaToMethod.java:197)
at com.sun.tools.javac.comp.LambdaToMethod.translate(LambdaToMethod.java:190)
at com.sun.tools.javac.comp.LambdaToMethod.translateTopLevelClass(LambdaToMethod.java:217)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1493)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1356)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1436)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1356)
at com.sun.tools.javac.main.JavaCompiler.compile2(JavaCompiler.java:901)
at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:860)
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.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:50)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:36)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:98)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:51)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:35)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:156)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:141)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:114)
at sun.reflect.GeneratedMethodAccessor363.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:50)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:124)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:113)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:95)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:73)
at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ResolveBuildCacheKeyExecuter.execute(ResolveBuildCacheKeyExecuter.java:66)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:596)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
at java.lang.Thread.run(Thread.java:748)



---------- BEGIN SOURCE ----------
The error happens during a module compile, not a specific file. The module has 100s of classes.
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None so far, I will try to modify the code

FREQUENCY : always