Android face detection doesn't work in a system app

Hello, I’m currently working on a system app that would run on an AOSP box.

I tried to recognize faces with cameraX, and got this error : E/MobileVisionBase: Error preloading model resource when calling process method on the FaceDetector

The sample app works fine on the box so I assume that my problem comes from the system app status. For information I use the bundle model.

Here is the full trace :

2020-07-27 15:53:07.084 11115-11115/fr.technosens.eliodroid.ebox E/MobileVisionBase: Error preloading model resource
    com.google.mlkit.common.MlKitException: Internal error has occurred when executing ML Kit tasks
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@16.0.0:28)
        at com.google.mlkit.common.sdkinternal.zzn.call(Unknown Source:6)
        at com.google.mlkit.common.sdkinternal.zzm.run(com.google.mlkit:common@@16.0.0:5)
        at com.google.mlkit.common.sdkinternal.zzq.run(com.google.mlkit:common@@16.0.0:3)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zzd(com.google.mlkit:common@@16.0.0:24)
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zza(com.google.mlkit:common@@16.0.0:30)
        at com.google.mlkit.common.sdkinternal.zzj.run(Unknown Source:2)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
        at java.lang.Thread.run(Thread.java:764)
     Caused by: java.lang.SecurityException: Failed to find provider com.google.android.gsf.gservices for user 0; expected to find a valid ContentProvider for this authority
        at android.os.Parcel.readException(Parcel.java:1951)
        at android.os.Parcel.readException(Parcel.java:1897)
        at android.content.IContentService$Stub$Proxy.registerContentObserver(IContentService.java:768)
        at android.content.ContentResolver.registerContentObserver(ContentResolver.java:1924)
        at android.content.ContentResolver.registerContentObserver(ContentResolver.java:1913)
        at com.google.android.gms.internal.vision.zzba.<init>(com.google.android.gms:play-services-vision-common@@19.1.0:11)
        at com.google.android.gms.internal.vision.zzba.zze(com.google.android.gms:play-services-vision-common@@19.1.0:5)
        at com.google.android.gms.internal.vision.zzbj.zzae(com.google.android.gms:play-services-vision-common@@19.1.0:71)
        at com.google.android.gms.internal.vision.zzbj.get(com.google.android.gms:play-services-vision-common@@19.1.0:50)
        at com.google.android.gms.internal.vision.zzlb.zzjq(com.google.android.gms:play-services-vision-common@@19.1.0:2)
        at com.google.android.gms.internal.vision.zzla.zzjq(com.google.android.gms:play-services-vision-common@@19.1.0:1)
        at com.google.android.gms.internal.vision.zzs.<init>(com.google.android.gms:play-services-vision-common@@19.1.0:14)
        at com.google.android.gms.vision.face.internal.client.zzb.<init>(com.google.android.gms:play-services-vision@@20.1.0:1)
        at com.google.android.gms.vision.face.FaceDetector$Builder.build(com.google.android.gms:play-services-vision@@20.1.0:40)
        at com.google.mlkit.vision.face.internal.zzd.load(com.google.android.gms:play-services-mlkit-face-detection@@16.1.0:37)
        at com.google.mlkit.common.sdkinternal.ModelResource.zza(com.google.mlkit:common@@16.0.0:22)
        at com.google.mlkit.common.sdkinternal.zzn.call(Unknown Source:6) 
        at com.google.mlkit.common.sdkinternal.zzm.run(com.google.mlkit:common@@16.0.0:5) 
        at com.google.mlkit.common.sdkinternal.zzq.run(com.google.mlkit:common@@16.0.0:3) 
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zzd(com.google.mlkit:common@@16.0.0:24) 
        at com.google.mlkit.common.sdkinternal.MlKitThreadPool.zza(com.google.mlkit:common@@16.0.0:30) 
        at com.google.mlkit.common.sdkinternal.zzj.run(Unknown Source:2) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) 
        at java.lang.Thread.run(Thread.java:764) 

Any idea to solve this issue ? Or did I missed something ?

Thanks

[sheepmaster]

So, a new ML Kit release came out yesterday, but the release doesn’t include com.google.android.gms:play-services-vision, which is where the fix is. I’ve filed an internal bug to include it in the next release, which should hopefully be in a few weeks.

[sheepmaster]

FYI, unobfuscated stack trace is here (internal only, sry). It looks like even though the app is using the bundled model, there is a code path that checks whether to use a particular variant of the Google Play Services model, which fails to find a ContentProvider in Google Play Services. From searching the error message, it seems that this does in fact happen when Google Play Services is not installed, but maybe there is something particular about your configuration that causes the exception but doesn’t in the “usual” AOSP configuration. In any case, this code path has recently been removed, so the crash should go away in the next release of ML Kit. Stay tuned 😃