title: cannot generate view binders java.util.NoSuchElementException with Android Gradle Plugin 2.1
body: <p>I'm using the binding mechanism in my Android project. All worked fine when using the Android Gradle Plugin until version 2.0. </p>
  
  <p>Since a couple of days I can upgrade to version 2.1 of the Android Gradle Plugin. When I upgrade I get the following exception:</p>
  
  <pre><code>java.lang.RuntimeException: failure, see logs for details.
  cannot generate view binders java.util.NoSuchElementException
          at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1113)
          at java.util.TreeMap$KeyIterator.next(TreeMap.java:1169)
          at android.databinding.tool.store.SetterStore$1.compare(SetterStore.java:82)
          at android.databinding.tool.store.SetterStore$1.compare(SetterStore.java:60)
          at java.util.TimSort.countRunAndMakeAscending(TimSort.java:324)
          at java.util.TimSort.sort(TimSort.java:189)
          at java.util.TimSort.sort(TimSort.java:173)
          at java.util.Arrays.sort(Arrays.java:659)
          at java.util.Collections.sort(Collections.java:217)
          at android.databinding.tool.store.SetterStore.getMultiAttributeSetterCalls(SetterStore.java:473)
          at android.databinding.tool.BindingTarget.resolveMultiSetters(BindingTarget.java:203)
          at android.databinding.tool.LayoutBinder.&lt;init&gt;(LayoutBinder.java:238)
          at android.databinding.tool.DataBinder.&lt;init&gt;(DataBinder.java:52)
          at android.databinding.tool.CompilerChef.ensureDataBinder(CompilerChef.java:83)
          at android.databinding.tool.CompilerChef.sealModels(CompilerChef.java:168)
          at android.databinding.annotationprocessor.ProcessExpressions.writeResourceBundle(ProcessExpressions.java:149)
          at android.databinding.annotationprocessor.ProcessExpressions.onHandleStep(ProcessExpressions.java:82)
          at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.runStep(ProcessDataBinding.java:154)
          at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.access$000(ProcessDataBinding.java:139)
          at android.databinding.annotationprocessor.ProcessDataBinding.process(ProcessDataBinding.java:66)
          at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:793)
          at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:722)
          at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$1700(JavacProcessingEnvironment.java:97)
          at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1029)
          at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1163)
          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)
          at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:132)
          at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:45)
          at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:33)
          at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:103)
          at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:52)
          at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:38)
          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:157)
          at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:139)
          at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:93)
          at com.android.build.gradle.tasks.factory.AndroidJavaCompile.compile(AndroidJavaCompile.java:49)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:606)
          at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:244)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:220)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:231)
          at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:209)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
          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:52)
          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.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:203)
          at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:185)
          at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:66)
          at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:50)
          at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:25)
          at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:110)
          at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:37)
          at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
          at org.gradle.execution.DefaultBuildExecuter.access$000(DefaultBuildExecuter.java:23)
          at org.gradle.execution.DefaultBuildExecuter$1.proceed(DefaultBuildExecuter.java:43)
          at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
          at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
          at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:30)
          at org.gradle.initialization.DefaultGradleLauncher$4.run(DefaultGradleLauncher.java:154)
          at org.gradle.internal.Factories$1.create(Factories.java:22)
          at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
          at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:52)
          at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:151)
          at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:32)
          at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:99)
          at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:93)
          at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
          at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:62)
          at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:93)
          at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:82)
          at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:94)
          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:43)
          at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:28)
          at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:75)
          at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:45)
          at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:51)
          at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:28)
          at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:43)
          at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:170)
          at org.gradle.launcher.cli.CommandLineActionFactory$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 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:606)
          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 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:606)
          at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:30)
          at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:129)
          at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)
  </code></pre>
  
  <p>At the top there is a reference to a log file, but I have no idea which one. And there is no reference to any file in my project that is incorrect. </p>
  
  <p>Does anyone have any idea what is going wrong or how I can resolve this error?</p>