android gradle plugin 3.0.0-alpha2: Error inflating class android.support.v7.widget.FitWindowsLinearLayout

Question

after upgrading the android gradle plugin from 3.0.0-alpha1 to 3.0.0-alpha2 my application does not start anymore: part of the stacktrace:

05-27 09:14:57.692 3015-3015/com.tmtron.dscontrol2app.debug E/AndroidRuntime: FATAL EXCEPTION: main
  Process: com.tmtron.dscontrol2app.debug, PID: 3015
  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tmtron.dscontrol2app.debug/com.tmtron.dscontrol2.gui.MainActivity}: android.view.InflateException: Binary XML file line #17: Binary XML file line #17: Error inflating class android.support.v7.widget.FitWindowsLinearLayout
   Caused by: android.view.InflateException: Binary XML file line #17: Binary XML file line #17: Error inflating class android.support.v7.widget.FitWindowsLinearLayout
   Caused by: android.view.InflateException: Binary XML file line #17: Error inflating class android.support.v7.widget.FitWindowsLinearLayout
   Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.widget.FitWindowsLinearLayout" on path: DexPathList[[zip file "/data/app/com.tmtron.dscontrol2app.debug-ZE45jTeV6eTnNIeveAjAbw==/base.apk", zip file "/data/app/com.tmtron.dscontrol2app.debug-ZE45jTeV6eTnNIeveAjAbw==/split_lib_dependencies_apk.apk", zip file "/data/app/com.tmtron.dscontrol2app.debug-ZE45jTeV6eTnNIeveAjAbw==/split_lib_slice_0_apk.apk", zip file "/data/app/com.tmtron.dscontrol2app.debug-..."/data/app/com.tmtron.dscontrol2app.debug-ZE45jTeV6eTnNIeveAjAbw==/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/com.tmtron.dscontrol2app.debug-ZE45jTeV6eTnNIeveAjAbw==/lib/x86, /system/lib, /system/vendor/lib]]
      at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:93)
      at com.tmtron.dscontrol2.gui.MainActivity.onCreate(MainActivity.java:41)
      at android.app.Activity.performCreate(Activity.java:6954)
05-27 09:14:57.693 3015-3015/com.tmtron.dscontrol2app.debug E/AndroidRuntime:     
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)

It seems like the class android.support.v7.widget.FitWindowsLinearLayout is not found anymore.

Any ideas?

BTW: I have already tried to do all kinds of cleanup, invalidate-caches, restart, etc. as mentioned in this SO.

Answer 1

I think this is a temporarily bug. Proparbly Proguard removes this class because of some reason, therefore this exception occurs. For now the easiest solution might be to disable Proguard in the build.gradle file. If you still want to keep it, you will have to change your proguard settings.

This is what I did and what worked for me:

-dontwarn android.support.v7.**
-keep class android.support.v7.widget.** { *; }

As I also had issues with constraint and design libray I added this:

-dontwarn android.support.constraint.** -keep class android.support.constraint.** { *; } -dontwarn android.support.design.** -keep class android.support.design.** { *; }

I hope it helps you:)