[Bug] Flaky crash at CrashlyticsReportDataCapture.java

[REQUIRED] Please fill in the following fields:

• Unity editor version: 2020.3.38
• Firebase Unity SDK version: 10.1.1
• Source you installed the SDK: .unitypackage
• Problematic Firebase Component: Crashlytics
• Other Firebase Components in use: Analytics
• Additional SDKs you are using:AdMob, etc.
• Platform you are using the Unity editor on: Windows
• Platform you are targeting: Android
• Scripting Runtime: IL2CPP
• Pre-built SDK from the website or open-source from this repo: _____

[REQUIRED] Please describe the issue here:

I have such errors in Crashlytics console. Don’t know how to reproduce.

0
VMStack.java
dalvik.system.VMStack.getThreadStackTrace
1
Thread.java - Line 580
java.lang.Thread.getStackTrace + 580
2
Thread.java - Line 522
java.lang.Thread.getAllStackTraces + 522
3
CrashlyticsReportDataCapture.java - Line 295
com.google.firebase.crashlytics.internal.common.CrashlyticsReportDataCapture.populateThreadsList + 295
4
CrashlyticsReportDataCapture.java - Line 266
com.google.firebase.crashlytics.internal.common.CrashlyticsReportDataCapture.populateExecutionData + 266
5
CrashlyticsReportDataCapture.java - Line 216
com.google.firebase.crashlytics.internal.common.CrashlyticsReportDataCapture.populateEventApplicationData + 216
6
CrashlyticsReportDataCapture.java - Line 102
com.google.firebase.crashlytics.internal.common.CrashlyticsReportDataCapture.captureEventData + 102
7
SessionReportingCoordinator.java - Line 274
com.google.firebase.crashlytics.internal.common.SessionReportingCoordinator.persistEvent + 274
8
SessionReportingCoordinator.java - Line 127
com.google.firebase.crashlytics.internal.common.SessionReportingCoordinator.persistFatalEvent + 127
9
CrashlyticsController.java - Line 203
com.google.firebase.crashlytics.internal.common.CrashlyticsController$2.call + 203
10
CrashlyticsController.java - Line 188
com.google.firebase.crashlytics.internal.common.CrashlyticsController$2.call + 188
11
CrashlyticsBackgroundWorker.java - Line 105
com.google.firebase.crashlytics.internal.common.CrashlyticsBackgroundWorker$3.then + 105
12
com.google.android.gms:play-services-tasks@@18.0.2 - Line 1
com.google.android.gms.tasks.zze.run + 1
13
ThreadPoolExecutor.java - Line 1112
java.util.concurrent.ThreadPoolExecutor.runWorker + 1112
14
ThreadPoolExecutor.java - Line 587
java.util.concurrent.ThreadPoolExecutor$Worker.run + 587
15
ExecutorUtils.java - Line 64
com.google.firebase.crashlytics.internal.common.ExecutorUtils$1$1.onRun + 64

16
BackgroundPriorityRunnable.java - Line 27
com.google.firebase.crashlytics.internal.common.BackgroundPriorityRunnable.run + 27

17
Thread.java - Line 818
java.lang.Thread.run + 818

[tianxiatianshan]

We also encountered this problem, hope someone can help solve it as soon as possible.

[mrober]

We have rolled out a fix for this in the Crashlytics backend. Java-wrapped Unity native crashes will be clustered into their own, more meaningful, issues now. If this problem persists, feel free to reopen this, file a new issue, or reach out to Firebase support.

The problem was that the Crashlytics SDK does not know the difference between a real uncaught exception (normal Java/Kotlin crash), and Unity calling the uncaught exception handler with a Java wrapped native crash on the next launch. So in this case, Crashlytics was adding a snapshot of all threads at the next launch time to the crash report, which has nothing to do with the threads at crash time. This was causing Crashlytics to get confused, and sometimes blame the SDK for the crash.