IssueTracker

Component used: androidx.work:work-runtime:2.1.0-beta01
Version used: 2.1.0-beta01
Devices/Android versions reproduced on: Android 7.1, Android 8.1, Android 9 / W_P200 (W_P200), Xperia Z5 Compact (E5823), ZenFone, Xperia Z5 Compact, V30, FP2, ...

I'm not able to reproduce but I can see a significant number of crash at production live

java.lang.RuntimeException:
  at android.app.ActivityThread.handleCreateService (ActivityThread.java:3265)
  at android.app.ActivityThread.-wrap5 (ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1598)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:241)
  at android.app.ActivityThread.main (ActivityThread.java:6274)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:886)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:776)
Caused by: java.lang.IllegalStateException:
  at androidx.work.impl.WorkManagerImpl.getInstance (WorkManagerImpl.java:142)
  at androidx.work.impl.background.systemjob.SystemJobService.onCreate (SystemJobService.java:53)
  at android.app.ActivityThread.handleCreateService (ActivityThread.java:3255)
  at android.app.ActivityThread.-wrap5 (ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1598)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:241)
  at android.app.ActivityThread.main (ActivityThread.java:6274)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:886)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:776)

My detailed finding is as follow. So far, I have no idea how it happens. I cross post at https://stackoverflow.com/questions/56729702/call-workmanagerimpl-getinstance-in-background-systemjob-systemjobservice-oncrea (Easier to read due to better formatting)

We are using the following WorkManager library

def work_version = "2.1.0-beta01"
implementation "androidx.work:work-runtime:$work_version"
Our Application class is being modified as follow so that it will work well with WorkManager

public class WeNoteApplication extends MultiDexApplication implements DefaultLifecycleObserver, Configuration.Provider {

    private static WeNoteApplication me;

    @Override
    public void onCreate() {
        super.onCreate();

        me = this;

        ...
    }

   public static WeNoteApplication instance() {
        return me;
    }

    @NonNull
    @Override
    public Configuration getWorkManagerConfiguration() {
        return new Configuration.Builder()
                .build();
    }
}
We do not add any WorkManager related code in AndroidManifest.xml. We solely rely on Default initialization

This is how we construct WorkManager

public static WorkManager getWorkManager() {
    WeNoteApplication weNoteApplication = WeNoteApplication.instance();
    return WorkManager.getInstance(weNoteApplication);
}
The above function is called in 4 different places

Activity
Fragment
BroadcastReceiver
IntentService
Still, we receive the following crash log in production. It happens in Android 7.1, Android 8.1, Android 9 (so far)

java.lang.RuntimeException:
  at android.app.ActivityThread.handleCreateService (ActivityThread.java:3265)
  at android.app.ActivityThread.-wrap5 (ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1598)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:241)
  at android.app.ActivityThread.main (ActivityThread.java:6274)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:886)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:776)
Caused by: java.lang.IllegalStateException:
  at androidx.work.impl.WorkManagerImpl.getInstance (WorkManagerImpl.java:142)
  at androidx.work.impl.background.systemjob.SystemJobService.onCreate (SystemJobService.java:53)
  at android.app.ActivityThread.handleCreateService (ActivityThread.java:3255)
  at android.app.ActivityThread.-wrap5 (ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1598)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:241)
  at android.app.ActivityThread.main (ActivityThread.java:6274)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:886)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:776)
As you can see in the crash, the crash origins from WorkManager internally, and not from our app.

By looking at https://android.googlesource.com/platform/frameworks/support/+/androidx-master-dev/work/workmanager/src/main/java/androidx/work/impl/WorkManagerImpl.java#142

WorkManagerImpl
/**
 * Retrieves the singleton instance of {@link WorkManagerImpl}.
 *
 * @param context A context for on-demand initialization.
 * @return The singleton instance of {@link WorkManagerImpl}
 * @hide
 */
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
public static @NonNull WorkManagerImpl getInstance(@NonNull Context context) {
    synchronized (sLock) {
        WorkManagerImpl instance = getInstance();
        if (instance == null) {
            Context appContext = context.getApplicationContext();
            if (appContext instanceof Configuration.Provider) {
                initialize(
                        appContext,
                        ((Configuration.Provider) appContext).getWorkManagerConfiguration());
                instance = getInstance(appContext);
            } else {
                throw new IllegalStateException("WorkManager is not initialized properly.  You "
                        + "have explicitly disabled WorkManagerInitializer in your manifest, "
                        + "have not manually called WorkManager#initialize at this point, and "
                        + "your Application does not implement Configuration.Provider.");
            }
There are 2 possibilities of the crash

appContext is null. (How can it be null?)
appContext does not implement Configuration.Provider (But we already implement in our WeNoteApplication?)
To figure out how context is being passed to WorkManagerImpl from SystemJobService, we look at the code of  androidx.work.impl.background.systemjob.SystemJobService.onCreate

SystemJobService
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
@RequiresApi(WorkManagerImpl.MIN_JOB_SCHEDULER_API_LEVEL)
public class SystemJobService extends JobService implements ExecutionListener {
    private static final String TAG = Logger.tagWithPrefix("SystemJobService");
    private WorkManagerImpl mWorkManagerImpl;
    private final Map<String, JobParameters> mJobParameters = new HashMap<>();
    @Override
    public void onCreate() {
        super.onCreate();
        mWorkManagerImpl = WorkManagerImpl.getInstance(getApplicationContext());
Look fine at first sight. But, why WorkManagerImpl cannot obtain Configuration.Provider although I already implement Configuration.Provider in my Application? Is it because I'm using MultiDexApplication?