title: Android Studio :Null pointer exception when assembleDebugUnitTest gradle task is run
body: <p>I am trying to run a simple JUNIT test for a test class in android studio. Build goes fine. When i try to run the JUNIT test i get the following error</p>
  
  <p>*</p>
  
  <pre><code>Execution failed for task ':app:mockableAndroidJar'.
  &gt; java.lang.NullPointerException (no error message)
  </code></pre>
  
  <p>*</p>
  
  <p>When i dumped the stacktrace i get the following. I am clueless as to why this is happening.</p>
  
  <pre><code>:
  org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:mockableAndroidJar'.
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteAc
  tionsTaskExecuter.java:69)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTa
  skExecuter.java:46)
          at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecu
  tionAnalysisTaskExecuter.java:35)
          at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskEx
  ecuter.java:64)
          at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecut
  er.java:58)
          at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptyS
  ourceFilesTaskExecuter.java:42)
          at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithN
  oActionsExecuter.java:52)
          at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecut
  er.java:53)
          at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMost
  OnceTaskExecuter.java:43)
          at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:31
  0)
          at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(Abst
  ractTaskPlanExecutor.java:79)
          at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(Abst
  ractTaskPlanExecutor.java:63)
          at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTask
  PlanExecutor.java:51)
          at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java
  :23)
          at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.ja
  va:88)
          at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:3
  7)
          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:14
  9)
          at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
          at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
          at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessB
  uildActionExecuter.java:90)
          at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.
  java:28)
          at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
          at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.
  java:41)
          at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.
  java:28)
          at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSugges
  tingBuildActionExecuter.java:50)
          at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSugges
  tingBuildActionExecuter.java:27)
          at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:40)
          at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:169)
          at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineAct
  ionFactory.java:237)
          at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineAct
  ionFactory.java:210)
          at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.jav
  a:35)
          at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.jav
  a:24)
          at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFacto
  ry.java:206)
          at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFacto
  ry.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)
          at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:33)
          at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:130)
          at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:48)
  Caused by: java.lang.NullPointerException
          at org.objectweb.asm.MethodWriter.visitMaxs(Unknown Source)
          at org.objectweb.asm.tree.MethodNode.accept(Unknown Source)
          at org.objectweb.asm.tree.MethodNode.accept(Unknown Source)
          at org.objectweb.asm.tree.ClassNode.accept(Unknown Source)
          at com.android.builder.testing.MockableJarGenerator.rewriteClass(MockableJarGenerator.java:134
  )
          at com.android.builder.testing.MockableJarGenerator.createMockableJar(MockableJarGenerator.jav
  a:91)
          at com.android.build.gradle.internal.tasks.MockableAndroidJarTask.createMockableJar(MockableAn
  droidJarTask.groovy:50)
          at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAct
  ion.doExecute(AnnotationProcessingTaskFactory.java:226)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAct
  ion.execute(AnnotationProcessingTaskFactory.java:219)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAct
  ion.execute(AnnotationProcessingTaskFactory.java:208)
          at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:589)
          at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:572)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteAct
  ionsTaskExecuter.java:80)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteAc
  tionsTaskExecuter.java:61)
          ... 49 more
  </code></pre>
  
  <p>Test Environment used:</p>
  
  <p>Environment: 1.2.2
  SDK Version : API 21
  Build tools 22.0.1
  Android Plugin version : 1.2.3
  Gradle version : 2.5
  JDK : 1.7.0_79</p>
  
  <p>Can you please help me out with this? Is there any problem with my setup?</p>
  
  <p>Build Gradle file:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  
  android {
      compileSdkVersion 21
      buildToolsVersion "22.0.1"
  
      defaultConfig {
          applicationId "com.example.krishnaswamyna.testmathsapplication"
          minSdkVersion 21
          targetSdkVersion 21
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(include: ['*.jar'], dir: 'libs')
      compile 'com.android.support:recyclerview-v7:22.2.1'
      compile 'com.android.support:leanback-v17:22.2.1'
      testCompile 'junit:junit:4.12'
      testCompile 'org.mockito:mockito-core:2.0.31-beta'
      testCompile 'org.robolectric:robolectric:3.0'
  }
  </code></pre>