Android Gradle Exception: "Multiple dex files define", duplicated classes under exploded-aar

Question

I'm trying to use my aar-library (a maven project, built with the android-maven-plugin by Jayway) in a gradle project but, when I run gradle assembleDebug, I'm having the following exception:

UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dex.DexException: Multiple dex files define   Lcom/google/android/gms/actions/ItemListIntents;
at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596)
at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554)
at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535)
at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
at com.android.dx.merge.DexMerger.merge(DexMerger.java:189)
at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:502)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:334)
at com.android.dx.command.dexer.Main.run(Main.java:277)
at com.android.dx.command.dexer.Main.main(Main.java:245)
at com.android.dx.command.Main.main(Main.java:106)

If I search that class in my project, Android Studio finds two results:

• ListItemIntents (com.google.android.gms.action) play-services-base-7.0.0(classes.jar)
• ListItemIntents (com.google.android.gms.action) aar-library(classes.jar)

Running the inspection gradle dependencyInsight --dependency play-services-base --configuration compile I get:

com.google.android.gms:play-services-base:7.0.0
+--- com.google.android.gms:play-services-gcm:7.0.0
|    \--- aar-library:core:1.0.10-SNAPSHOT
|         \--- compile                
+--- com.google.android.gms:play-services-location:7.0.0
|    \--- com.nexse.mobile.betting.core:core:1.0.10-SNAPSHOT (*)
\--- com.google.android.gms:play-services-maps:7.0.0
     \--- com.google.android.gms:play-services-location:7.0.0 (*)

(*) - dependencies omitted (listed previously)

The problem is in aar-library classes.jar: ListIntentIntents (and, obviously, the whole play-services-base module) is already there! So inside

my-gradle-project/app/build/intermediates/exploded-aar/

I have two references of play-services-base module: one under com.google.android.gms folder, one under aar-library folder

What should I do?

Answer 1

I've found the culprit! I was using the old android maven plugin com.jayway.maven.plugins.android.generation2

The new one com.simpligility.maven.plugins fixed the error.

Anyway thanks for the help.