Java.util.ConcurrentModificationException en las pruebas de JUnit

Esta es una especie de disparo en la oscuridad. Estoy recibiendo el error siguiente de vez en cuando al ejecutar mi unidad de prueba de unidad robolectric:

java.util.ConcurrentModificationException at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:966) at java.util.LinkedList$ListItr.next(LinkedList.java:888) at org.robolectric.shadows.ShadowResources.getOverlayedThemeValue(ShadowResources.java:294) at org.robolectric.shadows.ShadowResources.findAttributeValue(ShadowResources.java:284) at org.robolectric.shadows.ShadowResources.attrsToTypedArray(ShadowResources.java:187) at org.robolectric.shadows.ShadowResources.access$000(ShadowResources.java:51) at org.robolectric.shadows.ShadowResources$ShadowTheme.obtainStyledAttributes(ShadowResources.java:489) at android.content.res.Resources$Theme.obtainStyledAttributes(Resources.java) at android.content.Context.obtainStyledAttributes(Context.java:416) at android.view.View.__constructor__(View.java:3317) at org.robolectric.util.ReflectionHelpers$3.run(ReflectionHelpers.java:144) at org.robolectric.util.ReflectionHelpers.traverseClassHierarchy(ReflectionHelpers.java:241) at org.robolectric.util.ReflectionHelpers.callInstanceMethod(ReflectionHelpers.java:138) at org.robolectric.internal.Shadow.invokeConstructor(Shadow.java:73) at org.robolectric.shadows.ShadowView.__constructor__(ShadowView.java:109) at android.view.View.<init>(View.java) at android.widget.TextView.<init>(TextView.java) at com.getbase.floatingactionbutton.FloatingActionsMenu.createLabels(FloatingActionsMenu.java:461) at com.getbase.floatingactionbutton.FloatingActionsMenu.onFinishInflate(FloatingActionsMenu.java:447) at android.view.LayoutInflater.rInflate(LayoutInflater.java:763) at android.view.LayoutInflater.rInflate(LayoutInflater.java:758) at android.view.LayoutInflater.rInflate(LayoutInflater.java:758) at android.view.LayoutInflater.inflate(LayoutInflater.java:492) at android.view.LayoutInflater.inflate(LayoutInflater.java:397) at android.view.LayoutInflater.inflate(LayoutInflater.java:353) at android.support.v7.app.ActionBarActivityDelegateBase.setContentView(ActionBarActivityDelegateBase.java:228) at android.support.v7.app.ActionBarActivity.setContentView(ActionBarActivity.java:102) at com.myapp.app.view.activity.MainActivityActivity.onCreate(MainActivityActivity.java:75) at android.app.Activity.performCreate(Activity.java:5133) at org.robolectric.util.ReflectionHelpers$3.run(ReflectionHelpers.java:144) at org.robolectric.util.ReflectionHelpers.traverseClassHierarchy(ReflectionHelpers.java:241) at org.robolectric.util.ReflectionHelpers.callInstanceMethod(ReflectionHelpers.java:138) at org.robolectric.util.ActivityController$1.run(ActivityController.java:114) at org.robolectric.shadows.ShadowLooper.runPaused(ShadowLooper.java:309) at org.robolectric.shadows.CoreShadowsAdapter$2.runPaused(CoreShadowsAdapter.java:47) at org.robolectric.util.ActivityController.create(ActivityController.java:110) at com.myapp.app.BaseActivityRobolectricTest.startActivity(BaseActivityRobolectricTest.java:58) at com.myapp.app.BaseActivityRobolectricTest.startActivity(BaseActivityRobolectricTest.java:34) at com.myapp.app.view.activity.MainActivityActivityTest.setupActivity(MainActivityActivityTest.java:52) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24) at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:234) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:167) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:86) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:49) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:69) at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:48) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.messaging.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32) at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93) at com.sun.proxy.$Proxy2.processTestClass(Unknown Source) at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:105) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.messaging.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:360) at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) 

Estoy teniendo un horrible tiempo haciendo luz de este stacktrace y lo que podría estar pasando. ¿Alguien se ha topado con esto y ha encontrado una solución?

• Android Studio + Robolectric + Gradle Class Not Found Excepción
• Roboeléctrico con test.R.java
• Robolectric 3.0 java.lang.NoSuchMethodException en crear actividad
• Android Robolectric unidad de prueba de Marshmallow PermissionHelper
• Prueba de ActiveAndroid con Robolectric

Encontré un problema en el github de Robolectric que sugiere hacer un clean antes de ejecutar las pruebas. Aunque parece reducir al mínimo el número de veces que esta prueba falla, todavía falla ocasionalmente.

MainActivityActivity.java:75 es setContentView(R.layout.activity_main);

La prueba:

 @Before public void setupActivity() { setupAuthObjectGraphWithFakeData(); startActivity(RequestReviewsActivity.class, new ParentModule(), null); } protected void startActivity(Class<T> activityClass, Object module, Intent intent) { mActivityController = buildActivity(activityClass); if(intent != null) { mActivityController.withIntent(intent); } mActivity = mActivityController.get(); List<Object> modules = new ArrayList<>(); modules.addAll(mActivity.getModules()); modules.add(module); ObjectGraph objectGraph; if(mActivity instanceof AuthedActivity) { objectGraph = BaseApplication.getInstance().getAuthObjectGraph().plus(modules.toArray()); } else { objectGraph = BaseApplication.getInstance().getAppObjectGraph().plus(modules.toArray()); } mActivity.setObjectGraph(objectGraph); mActivityController.create(mBundle).start().resume(); } @Test public void testViewsAreAvailable() { assertThat(getActivity().mToolbar).isNotNull(); assertThat(getActivity().mContent).isNotNull(); assertThat(getActivity().mContentShadow).isNotNull(); assertThat(getActivity().mRequestRootFab).isNotNull(); assertThat(getActivity().mRequestReviewsList).isNotNull(); assertThat(getActivity().mRequestReviewsMainContent).isNotNull(); } 

Actualizar:

Este problema desaparece cuando no se realizan pruebas unitarias específicas de actividad (similares a las siguientes). Por el momento he tenido que comentar estas pruebas.

Estoy siguiendo generalmente el acercamiento de Robolectric encontrado aquí – http://blog.blundell-apps.com/android-gradle-app-with-robolectric-junit-tests/ con algunas actualizaciones (puesto que ese artículo es un pedacito viejo).

Estoy ejecutando las pruebas con una ./gradlew test

 public class App extends Application { @Override public void onCreate() { super.onCreate(); setupCrashReporting(); } protected void setupCrashReporting() { CrashlyticsCore core = new CrashlyticsCore.Builder() .disabled(BuildConfig.DEBUG) .build(); Crashlytics crashlytics = new Crashlytics.Builder() .core(core) .build(); Fabric.with(this, crashlytics); } } 

 public class TestApp extends App { @Override protected void setupCrashReporting() { // Do nothing. } }