Develop Reference

Update Gradle to Version 7.0.2

Updating Gradle from version 4.2.0 to 7.0.2. ended up in an error during minifying with R8. (Using Java 1.8)
Unfortunately, the error message is not very telling (see below).
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete
at Version.fakeStackEntry(Version_3.0.69.java:0)
at com.android.tools.r8.utils.w.a(SourceFile:68)
at com.android.tools.r8.utils.w.a(SourceFile:28)
at com.android.tools.r8.utils.w.a(SourceFile:27)
at com.android.tools.r8.R8.a(R8.java:29)
at com.android.tools.r8.R8.run(R8.java:3)
at com.android.builder.dexing.R8Tool.runR8(r8Tool.kt:301)
at com.android.build.gradle.internal.tasks.R8Task$Companion.shrink(R8Task.kt:592)
at com.android.build.gradle.internal.tasks.R8Task.doTaskAction(R8Task.kt:443)
at com.android.build.gradle.internal.tasks.NonIncrementalTask$taskAction$$inlined$recordTaskAction$1.invoke(BaseTask.kt:63)
at com.android.build.gradle.internal.tasks.Blocks.recordSpan(Blocks.java:51)
at com.android.build.gradle.internal.tasks.NonIncrementalTask.taskAction(NonIncrementalTask.kt:94)
at jdk.internal.reflect.GeneratedMethodAccessor512.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104)
... 118 more
Caused by: java.lang.NullPointerException: Cannot invoke "com.android.tools.r8.graph.B.F()" because "<parameter1>" is null
Did anybody face / solve the same problem?

Kotlin room database crash on kotlin 1.2.40 version

after upgrading to kotlin 1.2.40 I have the following error at build:
e: [kapt] An exception occurred: java.lang.NoClassDefFoundError: org/jetbrains/kotlin/serialization/jvm/JvmProtoBufUtil
at me.eugeniomarletti.kotlin.metadata.KotlinClassMetadata$data$2.invoke(KotlinMetadata.kt:51)
at me.eugeniomarletti.kotlin.metadata.KotlinClassMetadata$data$2.invoke(KotlinMetadata.kt:50)
at kotlin.SynchronizedLazyImpl.getValue(Lazy.kt:131)
at me.eugeniomarletti.kotlin.metadata.KotlinClassMetadata.getData(KotlinMetadata.kt)
at android.arch.persistence.room.ext.KotlinMetadataProcessor$DefaultImpls.getParameterNames(KotlinMetadataProcessor.kt:33)
at android.arch.persistence.room.processor.PojoProcessor.getParameterNames(PojoProcessor.kt:73)
at android.arch.persistence.room.processor.PojoProcessor.getParamNames(PojoProcessor.kt:245)
at android.arch.persistence.room.processor.PojoProcessor.chooseConstructor(PojoProcessor.kt:263)
at android.arch.persistence.room.processor.PojoProcessor.doProcess(PojoProcessor.kt:207)
at android.arch.persistence.room.processor.PojoProcessor.access$doProcess(PojoProcessor.kt:73)
at android.arch.persistence.room.processor.PojoProcessor$process$1.invoke(PojoProcessor.kt:104)
at android.arch.persistence.room.processor.PojoProcessor$process$1.invoke(PojoProcessor.kt:73)
at android.arch.persistence.room.processor.cache.Cache$Bucket.get(Cache.kt:46)
at android.arch.persistence.room.processor.PojoProcessor.process(PojoProcessor.kt:101)
at android.arch.persistence.room.processor.EntityProcessor.doProcess(EntityProcessor.kt:68)
at android.arch.persistence.room.processor.EntityProcessor.access$doProcess(EntityProcessor.kt:50)
at android.arch.persistence.room.processor.EntityProcessor$process$1.invoke(EntityProcessor.kt:57)
at android.arch.persistence.room.processor.EntityProcessor$process$1.invoke(EntityProcessor.kt:50)
at android.arch.persistence.room.processor.cache.Cache$Bucket.get(Cache.kt:46)
at android.arch.persistence.room.processor.EntityProcessor.process(EntityProcessor.kt:56)
at android.arch.persistence.room.processor.DatabaseProcessor.processEntities(DatabaseProcessor.kt:248)
at android.arch.persistence.room.processor.DatabaseProcessor.doProcess(DatabaseProcessor.kt:63)
at android.arch.persistence.room.processor.DatabaseProcessor.process(DatabaseProcessor.kt:53)
at android.arch.persistence.room.RoomProcessor$DatabaseProcessingStep.process(RoomProcessor.kt:57)
at com.google.auto.common.BasicAnnotationProcessor.process(BasicAnnotationProcessor.java:318)
at com.google.auto.common.BasicAnnotationProcessor.process(BasicAnnotationProcessor.java:171)
at org.jetbrains.kotlin.kapt3.ProcessorWrapper.process(annotationProcessing.kt:131)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:794)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:705)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$1800(JavacProcessingEnvironment.java:91)
at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1039)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1180)
at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1170)
at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1068)
at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:87)
at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing$default(annotationProcessing.kt:45)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.runAnnotationProcessing(Kapt3Extension.kt:257)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.analysisCompleted(Kapt3Extension.kt:212)
at org.jetbrains.kotlin.kapt3.ClasspathBasedKapt3Extension.analysisCompleted(Kapt3Extension.kt:95)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM$analyzeFilesWithJavaIntegration$2.invoke(TopDownAnalyzerFacadeForJVM.kt:97)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:107)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:84)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:374)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:64)
at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:101)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:365)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:130)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:161)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:63)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:107)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:51)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:96)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:405)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:98)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:920)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:98)
at org.jetbrains.kotlin.daemon.common.DummyProfiler.withMeasure(PerfUtils.kt:137)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.checkedCompile(CompileServiceImpl.kt:950)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.doCompile(CompileServiceImpl.kt:919)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:404)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:346)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
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)
Caused by: java.lang.ClassNotFoundException: org.jetbrains.kotlin.serialization.jvm.JvmProtoBufUtil
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 77 more
After I changed to version 1.2.30 in my build-gradle the build worked, but now I have a mismatch between the version used by gradle (1.2.30) and the one bundled into the IDE plugin (1.2.40).
Is there anything I am doing wrong with the new kotlin version ? Or how can I downgrade to the 1.2.30 version ?
Thank you for the attention.

You can downgrade by downloading a plugin zip corresponding to your android studio version here: http://plugins.jetbrains.com/plugin/6954-kotlin
And use Settings | Plugins | Install plugin from disk and select the downloaded zip file.

The problem is that they've introduced a binary incompatibility in compiler-embeddable in Kotlin 1.2.40. There're a few options right now:
Downgrade Kotlin to the 1.2.30
Use the latest Kotlin version with the stable Room version (1.1.0). Then you must substitute the kotlin-compiler-embeddable dependency (see below).
Use the latest Kotlin version with the latest Room version (1.1.0-rc1). They've fix bug in RC1.
I'd use the 3d way and keep an eye on the Room's releases. But if you choose the 2nd one then you must insert this in your root build.gradle:
subprojects {
configurations.all {
resolutionStrategy {
eachDependency {
if (requested.name == "kotlin-compiler-embeddable") {
useVersion("1.2.30")
}
}
}
}
}

Could not get unknown property 'manifestFile'

in Android studio gradle versions
distributionUrl=https\://services.gradle.org/distributions-snapshots/gradle-4.5-20171123235935+0000-all.zip
classpath 'com.android.tools.build:gradle:3.1.0-alpha04'
its getting this error
Error:Could not get unknown property 'manifestFile' for task ':backend:generateDebugRFile' of type com.android.build.gradle.internal.res.GenerateLibraryRFileTask.
Trying to change gradle, Studio version etc no affect

First off, regular caveats about using pre-release (alpha) software apply: if you don't need to use the alpha for any particular reason, consider using the stable versions instead. Right now that means
Android Studio 3.0.1
Android Gradle Plugin 3.0.1 (a.k.a. com.android.tools.build:gradle:3.0.1)
With that out of the way....it could be that the 3.1.0-alpha04 plugin removed support for manifestFile, and some other plugin you're using still depends on that. After all, the tools team did remove the similarly-named manifestOutputFile in 3.0.
I tried building a project with
Gradle dist 4.4-rc-3
Android Gradle plugin 3.1.0-alpha04
Fabric Gradle plugin 1.25.0
that applied the fabric plugin and got an error message that looks a lot like the one you posted:
Caused by: groovy.lang.MissingPropertyException: Could not get unknown property 'manifestFile' for task ':libs:generateProdDebugRFile' of type com.android.build.gradle.internal.res.GenerateLibraryRFileTask.
at org.gradle.internal.metaobject.AbstractDynamicObject.getMissingProperty(AbstractDynamicObject.java:83)
at org.gradle.internal.metaobject.AbstractDynamicObject.getProperty(AbstractDynamicObject.java:61)
at com.android.build.gradle.internal.res.GenerateLibraryRFileTask_Decorated.getProperty(Unknown Source)
at com.crashlytics.tools.gradle.CrashlyticsPlugin.addPluginTasks(CrashlyticsPlugin.groovy:239)
at com.crashlytics.tools.gradle.CrashlyticsPlugin.this$2$addPluginTasks(CrashlyticsPlugin.groovy)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at com.crashlytics.tools.gradle.CrashlyticsPlugin$_addPluginTasksToLibraryVariantsIn_closure4.doCall(CrashlyticsPlugin.groovy:122)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.gradle.api.internal.ClosureBackedAction.execute(ClosureBackedAction.java:71)
at org.gradle.util.ConfigureUtil.configureTarget(ConfigureUtil.java:160)
at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:106)
at org.gradle.util.ConfigureUtil$1.execute(ConfigureUtil.java:123)
at org.gradle.internal.ImmutableActionSet$SingletonSet.execute(ImmutableActionSet.java:155)
at org.gradle.internal.MutableActionSet.execute(MutableActionSet.java:35)
at org.gradle.api.internal.DefaultDomainObjectCollection.doAdd(DefaultDomainObjectCollection.java:204)
at org.gradle.api.internal.DefaultDomainObjectCollection.add(DefaultDomainObjectCollection.java:198)
at com.android.build.gradle.LibraryExtension.addVariant(LibraryExtension.java:90)
at com.android.build.gradle.FeatureExtension.addVariant(FeatureExtension.java:108)
at com.android.build.gradle.internal.ApiObjectFactory.create(ApiObjectFactory.java:132)
at com.android.build.gradle.BasePlugin.lambda$createAndroidTasks$6(BasePlugin.java:709)
at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:81)
at com.android.build.gradle.BasePlugin.createAndroidTasks(BasePlugin.java:695)
at com.android.build.gradle.BasePlugin.lambda$null$4(BasePlugin.java:613)
at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:81)
at com.android.build.gradle.BasePlugin.lambda$createTasks$5(BasePlugin.java:609)
at org.gradle.internal.event.BroadcastDispatch$ActionInvocationHandler.dispatch(BroadcastDispatch.java:91)
at org.gradle.internal.event.BroadcastDispatch$ActionInvocationHandler.dispatch(BroadcastDispatch.java:80)
at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:42)
at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:230)
at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:149)
at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58)
at org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:324)
at org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:234)
at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:140)
at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:37)
at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
at com.sun.proxy.$Proxy26.afterEvaluate(Unknown Source)
at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:76)
... 81 more

Had a similar problem with Crashlytics integration and found that I needed to add
crashlytics { instantAppSupport true }
This was needed even though I am not using Instant Apps.
Found from this answer in SO

Gradle doesn't find my Android Annotations generated classes

I'm using gradle and intellij to build my android project. My generated java files are stored in the .aagen directory. I can import all these generated classes in my non generated classes. Still when I build my project with my build.gradle script this is the output.
/android/source/com/app/App.java:30: cannot find symbol
symbol : class TestActivity_
location: package com.ui
import com.ui.TestActivity_;
This is my error I got:
aused by: org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed; see the compiler error output for details.
at org.gradle.api.internal.tasks.compile.jdk6.Jdk6JavaCompiler.execute(Jdk6JavaCompiler.java:42)
at org.gradle.api.internal.tasks.compile.jdk6.Jdk6JavaCompiler.execute(Jdk6JavaCompiler.java:33)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:95)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:48)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:34)
at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:29)
at org.gradle.api.internal.tasks.compile.DelegatingJavaCompiler.execute(DelegatingJavaCompiler.java:20)
at org.gradle.api.internal.tasks.compile.IncrementalJavaCompilerSupport.execute(IncrementalJavaCompilerSupport.java:33)
at org.gradle.api.internal.tasks.compile.IncrementalJavaCompilerSupport.execute(IncrementalJavaCompilerSupport.java:24)
at org.gradle.api.tasks.compile.Compile.compile(Compile.java:68)
at org.gradle.api.internal.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:216)
at org.gradle.api.internal.BeanDynamicObject.invokeMethod(BeanDynamicObject.java:122)
at org.gradle.api.internal.CompositeDynamicObject.invokeMethod(CompositeDynamicObject.java:147)
at org.gradle.api.tasks.compile.JavaCompile_Decorated.invokeMethod(Unknown Source)
at org.gradle.util.ReflectionUtil.invoke(ReflectionUtil.groovy:23)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.doExecute(AnnotationProcessingTaskFactory.java:217)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:210)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:199)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:526)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:509)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
... 67 more

Error when building with Android Annotations

I'm using the guide here to integrate Android Annotations in my Eclipse project (no Maven). I've got the latest ADT running, and tried cleaning my project, double checking build paths and order/export, and turning annotations on and off, but whenever I add the Android Annotations jar to the entries under Java Compiler > Annotation Processing > Factory Path in Eclipse, I get this error:
Error
Mon Jul 15 18:01:05 PDT 2013
Errors running builder 'Java Builder' on project 'Shopping'.
java.lang.NoClassDefFoundError: org/androidannotations/annotations/EActivity
at org.androidannotations.AndroidAnnotationProcessor.getSupportedAnnotationTypes(AndroidAnnotationProcessor.java:601)
at org.eclipse.jdt.internal.compiler.apt.dispatch.ProcessorInfo.<init>(ProcessorInfo.java:58)
at org.eclipse.jdt.internal.apt.pluggable.core.dispatch.IdeAnnotationProcessorManager.discoverNextProcessor(IdeAnnotationProcessorManager.java:94)
at org.eclipse.jdt.internal.compiler.apt.dispatch.RoundDispatcher.round(RoundDispatcher.java:116)
at org.eclipse.jdt.internal.compiler.apt.dispatch.BaseAnnotationProcessorManager.processAnnotations(BaseAnnotationProcessorManager.java:159)
at org.eclipse.jdt.internal.apt.pluggable.core.dispatch.IdeAnnotationProcessorManager.processAnnotations(IdeAnnotationProcessorManager.java:134)
at org.eclipse.jdt.internal.compiler.Compiler.processAnnotations(Compiler.java:820)
at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:434)
at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:365)
at org.eclipse.jdt.internal.core.builder.BatchImageBuilder.compile(BatchImageBuilder.java:178)
at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:302)
at org.eclipse.jdt.internal.core.builder.BatchImageBuilder.build(BatchImageBuilder.java:60)
at org.eclipse.jdt.internal.core.builder.JavaBuilder.buildAll(JavaBuilder.java:254)
at org.eclipse.jdt.internal.core.builder.JavaBuilder.build(JavaBuilder.java:173)
at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:726)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:239)
at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:292)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:295)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:256)
at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:394)
at org.eclipse.core.internal.resources.Project$1.run(Project.java:618)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
at org.eclipse.core.internal.resources.Project.internalBuild(Project.java:597)
at org.eclipse.core.internal.resources.Project.build(Project.java:114)
at org.eclipse.jdt.internal.ui.util.CoreUtility$BuildJob.run(CoreUtility.java:161)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
Caused by: java.lang.ClassNotFoundException: org.androidannotations.annotations.EActivity
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 29 more
Anyone have a fix?

You might have copied the wrong of the 2 jars. Please check carefully, where you place the one with and without "api" in the name (as given on the configuration page).
Besides that I guess you have checked all steps from the trouble shooting section.

It turned out to be a bug with my snapshot of Android Annotations. Reverting to the stable 2.7.1 works!