react-native android app crashes with in release apk

Question

I have written one hybrid app which is using react-native-svg to render svg images in react-native views. Everything works perfectly. Today, When I created release apk for my app and deployed it to an emulator it crashed with an error:

E/AndroidRuntime: FATAL EXCEPTION: mqt_native_modules
Process: com.example.packagname, PID: 8574
java.lang.IllegalStateException: java.lang.NoSuchFieldException: mFill
  at com.horcrux.svg.q.a(Unknown Source:78)
at com.horcrux.svg.i$1.a(Unknown Source:9)
at com.horcrux.svg.aa.a(Unknown Source:22)
at com.horcrux.svg.i.b(Unknown Source:14)
at com.horcrux.svg.i.a(Unknown Source:10)
at com.horcrux.svg.t.a(Unknown Source:104)
at com.horcrux.svg.t.c(Unknown Source:25)
at com.horcrux.svg.t.a(Unknown Source:7)
at com.facebook.react.uimanager.u.a(Unknown Source:5)
at com.facebook.react.uimanager.ag.a(Unknown Source:56)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.a(Unknown Source:34)
at com.facebook.react.uimanager.ag.d(Unknown Source:83)
at com.facebook.react.uimanager.ag.e(Unknown Source:17)
at com.facebook.react.uimanager.UIManagerModule.onBatchComplete(Unknown Source:27)
at com.facebook.react.bridge.z.d(Unknown Source:30)
at com.facebook.react.bridge.CatalystInstanceImpl$a.onBatchComplete(Unknown Source:14)
at com.facebook.react.bridge.queue.NativeRunnable.run(Native Method)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at com.facebook.react.bridge.queue.a.dispatchMessage(Unknown Source:0)
at android.os.Looper.loop(Looper.java:164)
at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(Unknown Source:16)
at java.lang.Thread.run(Thread.java:764)
Caused by: java.lang.NoSuchFieldException: mFill
at java.lang.Class.getField(Class.java:1601)
at com.horcrux.svg.q.a(Unknown Source:41)
at com.horcrux.svg.i$1.a(Unknown Source:9) 
at com.horcrux.svg.aa.a(Unknown Source:22) 
at com.horcrux.svg.i.b(Unknown Source:14) 
at com.horcrux.svg.i.a(Unknown Source:10) 
at com.horcrux.svg.t.a(Unknown Source:104) 
at com.horcrux.svg.t.c(Unknown Source:25) 
at com.horcrux.svg.t.a(Unknown Source:7) 
at com.facebook.react.uimanager.u.a(Unknown Source:5) 
at com.facebook.react.uimanager.ag.a(Unknown Source:56) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.a(Unknown Source:34) 
at com.facebook.react.uimanager.ag.d(Unknown Source:83) 
at com.facebook.react.uimanager.ag.e(Unknown Source:17) 
at com.facebook.react.uimanager.UIManagerModule.onBatchComplete(Unknown Source:27) 
at com.facebook.react.bridge.z.d(Unknown Source:30) 
at com.facebook.react.bridge.CatalystInstanceImpl$a.onBatchComplete(Unknown Source:14) 
at com.facebook.react.bridge.queue.NativeRunnable.run(Native Method) 
at android.os.Handler.handleCallback(Handler.java:789) 
at android.os.Handler.dispatchMessage(Handler.java:98) 
at com.facebook.react.bridge.queue.a.dispatchMessage(Unknown Source:0) 
at android.os.Looper.loop(Looper.java:164) 
at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(Unknown Source:16) 
at java.lang.Thread.run(Thread.java:764) 

I see this problem only when I comment -dontobfuscate from the proguard-rule.pro file. I want to obfuscate my apk code(I can't control it.). I am using proguard file similar to the one shown in this example, https://github.com/magicismight/react-native-svg-example/blob/cfb788461efae0de367c97aadcc829cdeb959a8d/android/app/proguard-rules.pro

Has anyone else faced this issue? Any suggestion on , how can I stop my app from crashing without enabling -dontobfuscate in proguard-rules file?

Edit I am pretty new to android development and I am trying proguard for the first time. Any positive suggestions on how to debug such issues will be really helpful.

Answer 1

The problem is related to proguard. As is now stated in the readme (or this issue), you need to add the following line to your android/app/proguard-rules.pro file:

-keep public class com.horcrux.svg.** {*;}

Answer 2

This is proguard. It needs patience and tears :)

In your stacktrace easily can be see that you are trying to access mField by reflection. Any line that is using by reflection must be add to proguard exception.

Why you ask? Because it name will be changed so Class methods can't find it.