"Module 'com.google.guava:guava' has been rejected" error during unit tests compilation

[MyDogTom]

"Module 'com.google.guava:guava' has been rejected" error during unit tests compilation

[jjohannes]

Thanks for the reproduced @MyDogTom. I was finally able to track down the issue and fix it in 494bd46.

I don't know though, why upgrading ExoPlayer fixed it and why it exists in the first place. It must be related to in which order Gradle does things and this might also be a "bug" in Gradle itself (I am not sure).

Thanks again for reporting this and your patience. I will release a 31.1.1 version of the plugin with the fix.

[jjohannes]

Sorry, I was mistaken. I forgot that the plugin actually adds the conflict resolution rules already. So it should just work and there should be no need to add resolution rules for capability conflicts.

I tried to reproduce your issue and added a test with the Android plugin, but had no success. Would you be able to share a reproducer?

[jjohannes]

Hi @MyDogTom. The plugin is adding the com.google.guava:listenablefuture capability to Guava, because Guava contains that feature directly nowadays. And it removes a "hack" Guava is doing to upgrade to an empty listenablefuture.jar with version 9999.0-empty-to-avoid-conflict-with-guava so that you do not get that empty file on your classpath.

If you have something else depending on listenablefuture directly - e.g. androidx.concurrent:concurrent-futures - you will get a conflict (which you are seeing).

You need to add a resolution strategy for the capability to resolve the conflict:

  configurations.all {
        resolutionStrategy.capabilitiesResolution.withCapability("com.google.guava:listenablefuture") {
            selectHighestVersion()
        }
    }

[MyDogTom]

Thanks for your help!
I tried your snippet, but still received an error.

Could not determine the dependencies of task ':settings:mergeDebugUnitTestResources'.
> Could not resolve all task dependencies for configuration ':settings:debugUnitTestRuntimeClasspath'.
   > Could not resolve com.google.guava:guava:27.0.1-jre.
     Required by:
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:resources:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:sandbox:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:utils:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:plugins-maven-dependency-resolver:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:shadows-framework:4.7.2 > org.robolectric:nativeruntime:4.7.2
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:listenablefuture:1.0' also provided by [com.google.guava:listenablefuture:1.0(runtime), com.google.guava:guava:27.0.1-jre(androidRuntime)]
   > Could not resolve com.google.guava:listenablefuture:1.0.
     Required by:
         project :settings > project :base_ui > androidx.work:work-runtime:2.5.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0 > androidx.concurrent:concurrent-futures:1.0.0
      > Module 'com.google.guava:listenablefuture' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:listenablefuture:1.0' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime), com.google.guava:guava:27.1-android(runtime)]
   > Could not resolve com.google.guava:guava:27.1-android.
     Required by:
         project :settings > project :base-api > com.google.android.exoplayer:exoplayer:2.13.0 > com.google.android.exoplayer:exoplayer-core:2.13.0 > com.google.android.exoplayer:exoplayer-common:2.13.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:listenablefuture:1.0' also provided by [com.google.guava:listenablefuture:1.0(runtime), com.google.guava:guava:27.0.1-jre(androidRuntime)]

Then I thought that probably selectHighestVersion() is not able to choose between com.google.guava:listenablefuture:1.0, com.google.guava:guava:27.0.1-jre and com.google.guava:guava:27.1-android. I received these three by printing candidate.id.displayName.

Based on that assumption I excluded com.google.guava:listenablefuture:1.0 from resolution to ensure that it's never selected.

configuration.resolutionStrategy.capabilitiesResolution
    .withCapability("com.google.guava:listenablefuture") { resolution ->
        val onlyGuava = resolution.candidates.filter {
            it.id.displayName.startsWith("com.google.guava:guava")
        }
        val selected = onlyGuava.maxByOrNull {
            VersionNumber.parse(it.id.displayName.substringAfterLast(":"))
        }
        selected?.let {
            resolution.select(it)
        } ?: throw IllegalStateException("can't find resolution")
    }

this time the error was different

Could not determine the dependencies of task ':settings:mergeDebugUnitTestResources'.
> Could not resolve all task dependencies for configuration ':settings:debugUnitTestRuntimeClasspath'.
   > Could not resolve com.google.guava:guava:27.0.1-jre.
     Required by:
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:resources:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:sandbox:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:utils:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:plugins-maven-dependency-resolver:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:shadows-framework:4.7.2 > org.robolectric:nativeruntime:4.7.2
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.collections:google-collections:27.1' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]
   > Could not resolve com.google.guava:listenablefuture:1.0.
     Required by:
         project :settings > project :base_ui > androidx.work:work-runtime:2.5.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0 > androidx.concurrent:concurrent-futures:1.0.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.collections:google-collections:27.1' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]
   > Could not resolve com.google.guava:guava:27.1-android.
     Required by:
         project :settings > project :base-api > com.google.android.exoplayer:exoplayer:2.13.0 > com.google.android.exoplayer:exoplayer-core:2.13.0 > com.google.android.exoplayer:exoplayer-common:2.13.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.collections:google-collections:27.1' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]

Then I added resolution for com.google.collections:google-collections and com.google.guava:guava (next error I received) using selectHighestVersion.

configuration.resolutionStrategy
    .capabilitiesResolution
    .withCapability("com.google.collections:google-collections") { resolution ->
        resolution.selectHighestVersion()
    }
configuration.resolutionStrategy
    .capabilitiesResolution
    .withCapability("com.google.guava:guava") { resolution ->
        resolution.selectHighestVersion()
    }

This time compilation succeeded.

To be honest the final result looks a bit overcomplicated, but I guess it's the way to go, right?

[jjohannes]

That you also need to do com.google.collections:google-collections makes sense. But you should not need to do something for com.google.guava:guava. Also, the more complicated resolution you did should not be necessary - selectHighestVersion() should be enough.

com.google.guava:guava:27.0.1-jre and com.google.guava:guava:27.1-android should usually not turn up in the capability conflict. They are the same module (only with different versions).

Maybe there is indeed an issue with the plugin. I will try to reproduce the problem.

Which Gradle and Android versions are you using?

[MyDogTom]

Gradle 7.3.3 and AGP 7.0.4.

[MyDogTom]

But you should not need to do something for com.google.guava:guava.

btw, If I don't include resolution for com.google.guava:guava then I see the following error

> Could not resolve all task dependencies for configuration ':settings:debugUnitTestRuntimeClasspath'.
   > Could not resolve com.google.guava:guava:27.0.1-jre.
     Required by:
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:resources:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:sandbox:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:utils:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:plugins-maven-dependency-resolver:4.7.2
         project :settings > org.robolectric:robolectric:4.7.2 > org.robolectric:shadows-framework:4.7.2 > org.robolectric:nativeruntime:4.7.2
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:guava:27.1-android' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]
   > Could not resolve com.google.guava:listenablefuture:1.0.
     Required by:
         project :settings > project :base_ui > androidx.work:work-runtime:2.5.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0
         project :settings > project :navigation > androidx.browser:browser:1.3.0 > androidx.concurrent:concurrent-futures:1.0.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:guava:27.1-android' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]
   > Could not resolve com.google.guava:guava:27.1-android.
     Required by:
         project :settings > project :base-api > com.google.android.exoplayer:exoplayer:2.13.0 > com.google.android.exoplayer:exoplayer-core:2.13.0 > com.google.android.exoplayer:exoplayer-common:2.13.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:guava:27.1-android' also provided by [com.google.guava:guava:27.0.1-jre(androidRuntime)]

[MyDogTom]

Hi @jjohannes,
I added a simple project that produces similar error https://github.com/MyDogTom/GuavaReproduce

Failure happens after executing ./gradlew app:testDebugUnitTest.

[MyDogTom]

I've just noticed that if I bump ExoPlayer dependency to 2.16.0, then the issue is gone. With ExoPlayer 2.15.1 version the build still fails. I've quickly scanned ExoPlayer 2.16.0 changelog. The only change that seems to be related is

Upgrade the WorkManager extension to depend on androidx.work:work-runtime:2.7.0.

Still I don't have enough knowledge to find a complete explanation :(

[jeff-huston]

This fixed a build issue we were having, too - thanks @MyDogTom and @jjohannes!