Enhancing stacktraces from RxJava

[maskaravivek]

Stacktraces from RxJava callables are often not very helpful. They contain no trace of which line in our codebase caused the issue. For eg recently we were trying to figure out a play store crash #1545(C). The below stacktrace doesn't tell which part of the code led to NPE.

java.lang.NullPointerException: 
  at io.reactivex.internal.functions.ObjectHelper.requireNonNull (ObjectHelper.java:39)
  at io.reactivex.internal.operators.observable.ObservableFromCallable.subscribeActual (ObservableFromCallable.java:42)
  at io.reactivex.Observable.subscribe (Observable.java:10901)
  at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run (ObservableSubscribeOn.java:96)
  at io.reactivex.Scheduler$DisposeTask.run (Scheduler.java:452)
  at io.reactivex.internal.schedulers.ScheduledRunnable.run (ScheduledRunnable.java:61)
  at io.reactivex.internal.schedulers.ScheduledRunnable.call (ScheduledRunnable.java:52)
  at java.util.concurrent.FutureTask.run (FutureTask.java:237)
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201 (ScheduledThreadPoolExecutor.java:152)
  at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run (ScheduledThreadPoolExecutor.java:265)
  at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1112)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:587)
  at java.lang.Thread.run (Thread.java:818)

Is there a way to enhance these logs. I found a few libraries for the same:

• https://github.com/T-Spoon/Traceur
• https://github.com/akaita/RxJava2Debug

It would be great if someone who has experience with reactive programming could pitch in with suggestions?

@psh @whym

[maskaravivek]

Already incorporated. :)