Missing support-compat Dependency

[commonsguy]

Stetho needs android.support.v4.view.accessibility.AccessibilityNodeInfoCompat. However, it does not depend upon support-compat, the Android SDK artifact that (now) houses that class. As a result, if the project does not already have that dependency, Stetho crashes.

The attached project can be used to reproduce the problem. At the moment, support-compat is commented out in app/build.gradle. If you run the project, and you start navigating the view hierarchy using the Elements view, after a few layers, you eventually crash with:

java.lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v4/view/accessibility/AccessibilityNodeInfoCompat;
      at com.facebook.stetho.inspector.elements.android.ViewDescriptor.onGetAccessibilityStyles(ViewDescriptor.java:189)
      at com.facebook.stetho.inspector.elements.android.ViewDescriptor.onGetAccessibilityStyles(ViewDescriptor.java:40)
      at com.facebook.stetho.inspector.elements.AbstractChainedDescriptor.getAccessibilityStyles(AbstractChainedDescriptor.java:163)
      at com.facebook.stetho.inspector.elements.AbstractChainedDescriptor.getAccessibilityStyles(AbstractChainedDescriptor.java:162)
      at com.facebook.stetho.inspector.elements.Document.getElementAccessibilityStyles(Document.java:153)
      at com.facebook.stetho.inspector.protocol.module.CSS$2.run(CSS.java:150)
      at com.facebook.stetho.common.android.HandlerUtil$2.onRun(HandlerUtil.java:90)
      at com.facebook.stetho.common.android.HandlerUtil$2.onRun(HandlerUtil.java:87)
      at com.facebook.stetho.common.android.HandlerUtil$WaitableRunnable.run(HandlerUtil.java:109)
      at android.os.Handler.handleCallback(Handler.java:739)
      at android.os.Handler.dispatchMessage(Handler.java:95)
      at android.os.Looper.loop(Looper.java:148)
      at android.app.ActivityThread.main(ActivityThread.java:5417)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v4.view.accessibility.AccessibilityNodeInfoCompat" on path: DexPathList[[zip file "/data/app/com.commonsware.android.stetho-1/base.apk"],nativeLibraryDirectories=[/data/app/com.commonsware.android.stetho-1/lib/arm, /vendor/lib, /system/lib]]
      at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
      at com.facebook.stetho.inspector.elements.android.ViewDescriptor.onGetAccessibilityStyles(ViewDescriptor.java:189) 
      at com.facebook.stetho.inspector.elements.android.ViewDescriptor.onGetAccessibilityStyles(ViewDescriptor.java:40) 
      at com.facebook.stetho.inspector.elements.AbstractChainedDescriptor.getAccessibilityStyles(AbstractChainedDescriptor.java:163) 
      at com.facebook.stetho.inspector.elements.AbstractChainedDescriptor.getAccessibilityStyles(AbstractChainedDescriptor.java:162) 
      at com.facebook.stetho.inspector.elements.Document.getElementAccessibilityStyles(Document.java:153) 
      at com.facebook.stetho.inspector.protocol.module.CSS$2.run(CSS.java:150) 
      at com.facebook.stetho.common.android.HandlerUtil$2.onRun(HandlerUtil.java:90) 
      at com.facebook.stetho.common.android.HandlerUtil$2.onRun(HandlerUtil.java:87) 
      at com.facebook.stetho.common.android.HandlerUtil$WaitableRunnable.run(HandlerUtil.java:109) 
      at android.os.Handler.handleCallback(Handler.java:739) 
      at android.os.Handler.dispatchMessage(Handler.java:95) 
      at android.os.Looper.loop(Looper.java:148) 
      at android.app.ActivityThread.main(ActivityThread.java:5417) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Suppressed: java.lang.ClassNotFoundException: android.support.v4.view.accessibility.AccessibilityNodeInfoCompat
      at java.lang.Class.classForName(Native Method)
      at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
      at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
          ... 17 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available

If you uncomment the debugCompile 'com.android.support:support-compat:25.2.0' statement in Gradle, Stetho runs without issue.

Let me know if you need additional information — thanks!

Stetho.zip

[jasta]

Hmm I think this was actually a mistake in the accessibility diffs. We should not have a hard dependency on the compat library for accessibility but rather should be using the compat lib only if it's present and also using the framework version directly if it's available (we're running on the right platform version)

[jasta]

Looking at this closer, this was definitely a mistake. We're using support lib and compat library code without checking whether it's in the classpath which means that we now have an undeclared hard dependency on two libraries we explicitly didn't want to hard dep. I'm somewhat surprised we're not seeing more users complaining about this actually...

[blavalla]

#511 should resolve this issue. If you don't include the support library in your application it will simply disable the accessibility inspection feature.