Proguard-obfuscated stack traces incorrect in Firebase Crashlytics, even after uploading mapping file

Question

I have an Android app built with Android Studio using Gradle, and it uses Proguard for obfuscation. After uploading the .aab file to the Play Store, I noticed that the crashes reported in Firebase Crashlytics are incorrect. Here's an example of a stack trace:

Fatal Exception: java.lang.NullPointerException Attempt to read from field 'boolean d3.z0.D0' on a null object reference com.cbm.qmobile.ui.main.LinechartFragment.isOnViewCreatedCalled (LinechartFragment.java:23) com.cbm.qmobile.ui.main.ChildFragment.setNoDataText (ChildFragment.java:23) com.cbm.qmobile.ui.main.ChildFragment.lambda$onViewCreated$4 (ChildFragment.java:475)

The problem:

1. Line mismatch: In the LinechartFragment, line 23 is an import statement, so this line number in the stack trace is clearly incorrect.
2. Obfuscated symbols: 'boolean d3.z0.D0'? I understand this is due to obfuscation, but the stack trace is not being de-obfuscated properly, even after uploading the mapping file.

Here’s what I’ve done so far to try to resolve the issue:

1. Added mappingFileUploadEnabled true to my app-level build.gradle file:

   buildTypes {
       release {
           minifyEnabled true
           shrinkResources true
           proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
           firebaseCrashlytics {
               mappingFileUploadEnabled true
           }
       }
   }
   

   This didn’t make any difference.

2. Manually uploaded the mapping.txt file to the Play Console at: C:\Users\Makram\AndroidStudioProjects\QMobile\app\build\outputs\mapping\release\mapping.txt

   After doing this, it seems that the "Crashes and ANRs" section in the Play Console is now empty, which is puzzling.

Also I do know that I can simply add the follwing lines to the proguard-rules.pro file:

-keepattributes SourceFile,LineNumberTable
-renamesourcefileattribute SourceFile

However, I want to avoid this because:

• It increases the app's file size.
• It reduces security, and the mapping file should be sufficient for de-obfuscation.