title: Is it possible to enable -Werror for JavaCompile in gradle?
body: <p>I have an Android project setup in gradle using the com.android.application plugin.  I want javac lint warnings to trigger errors instead of just warnings.</p>
  
  <p>The following works just fine for warnings:</p>
  
  <pre><code>tasks.withType(JavaCompile).all {
      options.compilerArgs.add("-Xlint:all")
  }
  </code></pre>
  
  <p>However, adding -Werror to it:</p>
  
  <pre><code>tasks.withType(JavaCompile).all {
      options.compilerArgs.add("-Xlint:all")
      options.compilerArgs.add("-Werror")
  }
  </code></pre>
  
  <p>causes the build to completely fail (not in the right way):</p>
  
  <blockquote>
    <p>FAILURE: Build failed with an exception.</p>
    
    <p>* What went wrong: Execution failed for task ':app:compileDebugJava'.</p>
    
    <blockquote>
      <p>java.lang.NullPointerException</p>
    </blockquote>
    
    <p>* Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.</p>
    
    <p>BUILD FAILED</p>
  </blockquote>
  
  <p>Calling gradle with --stacktrace shows:</p>
  
  <blockquote>
    <p>* Exception is: org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileDebugJava'.  at
    org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:69)
      at
    org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
      at
    org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
      at
    org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
      at
    org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
      at
    org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
      at
    org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
      at
    org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
      at
    org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
      at
    org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:305)
      at
    org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(AbstractTaskPlanExecutor.java:79)
      at
    org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:63)
      at
    org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:51)
      at
    org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:23)
      at
    org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:88)
      at
    org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
      at
    org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
      at
    org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
      at
    org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:68)
      at
    org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
      at
    org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
      at
    org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:55)
      at
    org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:149)
      at
    org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
      at
    org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
      at
    org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:80)
      at
    org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
      at
    org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
      at
    org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:36)
      at
    org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
      at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:51)
      at
    org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:171)
      at
    org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
      at
    org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
      at
    org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
      at
    org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
      at
    org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
      at
    org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
      at
    org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
      at
    org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
      at org.gradle.launcher.Main.doAction(Main.java:33)  at
    org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)  at
    org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
      at
    org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
      at org.gradle.launcher.GradleMain.main(GradleMain.java:23) Caused by:
    java.lang.RuntimeException: java.lang.NullPointerException    at
    com.sun.tools.javac.main.Main.compile(Main.java:469)  at
    com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:132)    at
    org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:42)
      at
    org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:35)
      at
    org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:97)
      at
    org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:50)
      at
    org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:36)
      at
    org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:34)
      at
    org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
      at
    org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:158)
      at
    org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:138)
      at
    org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:92)
      at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
      at
    org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:235)
      at
    org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:211)
      at
    org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:222)
      at
    org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:200)
      at
    org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
      at
    org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
      ... 44 more Caused by: java.lang.NullPointerException   at
    dagger.internal.codegen.Util.getAnnotation(Util.java:192)     at
    dagger.internal.codegen.GraphAnalysisProcessor.process(GraphAnalysisProcessor.java:105)
      at
    com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:793)
      at
    com.sun.tools.javac.processing.JavacProcessingEnvironment.access$200(JavacProcessingEnvironment.java:97)
      at
    com.sun.tools.javac.processing.JavacProcessingEnvironment$DiscoveredProcessors$ProcessorStateIterator.runContributingProcs(JavacProcessingEnvironment.java:644)
      at
    com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1027)
      at
    com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1185)
      at
    com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1108)
      at
    com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:824)
      at com.sun.tools.javac.main.Main.compile(Main.java:439)     ... 62 more</p>
  </blockquote>
  
  <p>Is adding -Werror not supported?</p>