Create a sample android app?

[AttwellBrian]

I believe the README is missing something for Android. I tried to follow the instructions and found the following crash.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':demos:memory-leaks:compileDebugJavaWithJavac'.
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:98)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:68)
        at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:62)
        at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
        at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:88)
        at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:51)
        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$1.execute(DefaultTaskGraphExecuter.java:236)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.execute(DefaultTaskGraphExecuter.java:228)
        at org.gradle.internal.Transformers$4.transform(Transformers.java:169)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:106)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:61)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:228)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:215)
        at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:77)
        at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:58)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
        at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:46)
Caused by: org.gradle.internal.UncheckedException: java.lang.reflect.InvocationTargetException
        at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:45)
        at net.ltgt.gradle.errorprone.ErrorProneCompiler.execute(ErrorProneCompiler.java:75)
        at net.ltgt.gradle.errorprone.ErrorProneCompiler.execute(ErrorProneCompiler.java:24)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:99)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:52)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37)
        at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:35)
        at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
        at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:244)
        at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:229)
        at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:151)
        at com.android.build.gradle.tasks.factory.AndroidJavaCompile.compile(AndroidJavaCompile.java:49)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$IncrementalTaskAction.doExecute(DefaultTaskClassInfoStore.java:163)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:134)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:123)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.execute(ExecuteActionsTaskExecuter.java:115)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.execute(ExecuteActionsTaskExecuter.java:109)
        at org.gradle.internal.Transformers$4.transform(Transformers.java:169)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:106)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:56)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:109)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:90)
        ... 20 more
Caused by: java.lang.reflect.InvocationTargetException
        at net.ltgt.gradle.errorprone.ErrorProneCompiler.execute(ErrorProneCompiler.java:63)
        ... 41 more
Caused by: java.lang.RuntimeException: java.lang.NoClassDefFoundError: org/openjdk/source/tree/Tree
        at com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:158)
        at com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:96)
        at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:90)
        at com.google.errorprone.BaseErrorProneCompiler.run(BaseErrorProneCompiler.java:137)
        at com.google.errorprone.BaseErrorProneCompiler.run(BaseErrorProneCompiler.java:108)
        at com.google.errorprone.ErrorProneCompiler.run(ErrorProneCompiler.java:118)
        at com.google.errorprone.ErrorProneCompiler.compile(ErrorProneCompiler.java:65)
        ... 42 more
Caused by: java.lang.NoClassDefFoundError: org/openjdk/source/tree/Tree
        at com.google.googlejavaformat.java.filer.FormattingFiler.<init>(FormattingFiler.java:37)
        at com.google.googlejavaformat.java.filer.FormattingFiler.<init>(FormattingFiler.java:42)
        at dagger.internal.codegen.ComponentProcessor.initSteps(ComponentProcessor.java:66)
        at dagger.shaded.auto.common.BasicAnnotationProcessor.init(BasicAnnotationProcessor.java:119)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment$ProcessorState.<init>(JavacProcessingEnvironment.java:675)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment$DiscoveredProcessors$ProcessorStateIterator.next(JavacProcessingEnvironment.java:774)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:869)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$2200(JavacProcessingEnvironment.java:108)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1204)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1313)
        at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1267)
        at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:943)
        at com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:100)
        at com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:142)
        ... 48 more
Caused by: java.lang.ClassNotFoundException: org.openjdk.source.tree.Tree
        ... 62 more

Might be worthwhile to create an Android sample app that engineers can copy-and-paste.

[msridhar]

Are you using Dagger? There is a bad interaction between Dagger pre-2.12 and NullAway (or any Error Prone plugin); see #48. I can clarify in the README for sure, as it's come up multiple times now.

[msridhar]

@AttwellBrian I added a note to the README in the Android section. Please let us know if this fixes the problem or the root cause was something else.

[AttwellBrian]

It was dagger.