How to trace crashes from google play console to actual source

Question

I have an app on Google Play, and some users experiences crashes on my app like the code below (copied from my app crashes cluster on Google Developer Console)

The user affected uses ( Huawei Nexus 6P (angler), Android 8.1 )

My question is how to know which part on my actual code is returning this crash? I need to solve this crash. I have tried to use my app on an emulator of ( Huawei Nexus 6P (angler), Android 8.1 ) but I couldn't get this crash :(

java.lang.RuntimeException: 
  at android.os.AsyncTask$3.done (AsyncTask.java:353)
  at java.util.concurrent.FutureTask.finishCompletion (FutureTask.java:383)
  at java.util.concurrent.FutureTask.setException (FutureTask.java:252)
  at java.util.concurrent.FutureTask.run (FutureTask.java:271)
  at android.os.AsyncTask$SerialExecutor$1.run (AsyncTask.java:245)
  at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1162)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:636)
  at java.lang.Thread.run (Thread.java:764)
Caused by: java.lang.ExceptionInInitializerError: 
  at org.a.b.f$a.<init> (Unknown Source:3)
  at org.a.b.f.<init> (Unknown Source:13)
  at org.a.c.m.b (Unknown Source:12)
  at org.a.c.m.a (Unknown Source)
  at org.a.c.b.a (Unknown Source:7)
  at org.a.c.g.a (Unknown Source:25)
  at org.a.a.a.a (Unknown Source:21)
  at org.a.a.b$c.f (Unknown Source:23)
  at org.a.a.b.a (Unknown Source:12)
  at com.boy.appMyTest.a$a.a (Unknown Source:136)
  at com.boy.appMyTest.a$a.doInBackground (Unknown Source:2)
  at android.os.AsyncTask$2.call (AsyncTask.java:333)
  at java.util.concurrent.FutureTask.run (FutureTask.java:266)
Caused by: java.lang.IllegalStateException: 
  at org.a.b.i.b (Unknown Source:61)
  at org.a.b.i.a (Unknown Source)
  at org.a.b.i$b.<init> (Unknown Source:3)
  at org.a.b.i$b.<clinit> (Unknown Source:8)

Answer 1

Integrate Firebase Crashlytics

Firebase Crashlytics

Answer 2

I found a way to trace the crash manually.

Use the ProGuard retrace batch file on android SDK and the mapping file on your project folder located ( app\\build\\outputs\\mapping\\release ) then run the below command and it will print out the stack-trace of the crash on your code.

retrace.bat mapping.txt your_error_stacktrace.txt > stacktrace.txt