Proguard error: “Can't find common super class of …”

Question

I'm getting this error while building my app in Android Studio:

Unexpected error while performing partial evaluation:
  Class       = [com/google/android/gms/internal/zznc]
  Method      = [zza(Lcom/google/android/gms/internal/zzmk;Landroid/content/Context;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lcom/google/android/gms/internal/zznh;Lcom/google/android/gms/internal/zzgl;Lcom/google/android/gms/internal/zznb;)Lcom/google/android/gms/internal/zzmn;]
  Exception   = [java.lang.IllegalArgumentException] (Can't find common super class of [com/google/android/gms/internal/zzmn] (with 1 known super classes) and [java/lang/String] (with 2 known super classes))
Warning: Exception while processing task java.io.IOException: java.lang.IllegalArgumentException: Can't find common super class of [com/google/android/gms/internal/zzmn] (with 1 known super classes) and [java/lang/String] (with 2 known super classes)
:analytics_test_app:transformClassesAndResourcesWithProguardForDebug FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':analytics_test_app:transformClassesAndResourcesWithProguardForDebug'.
> Job failed, see logs for details

How can I solve that?

Answer 1

Do you have different versions of different Play Service libraries? Make sure you use the same version for all libraries:

implementation 'com.google.android.gms:play-services-analytics:16.0.1'
implementation 'com.google.android.gms:play-services-auth:11.8.0' // should be the same version

Some versions have different implementations and APIs, which causes internal conflicts that also affects Proguard.