Bug Crash on Android when Unity ARCore session reset called when unloading a blended AR scene

Since upgrading to AR-Foundation 4.2.8 from 4.2.3 this issue has affected 155 users, logs indicate they were closing the AR scene. We Destroy all items in AR-planes.trackables, then call reset on the AR session before Async unloading the scene.

Details:
Unity version 2021.3.9f1
ARFoundation version 4.2.8
ARCore XR Plugin version 4.2.8
Affected 155 users in last 7 days.
Affected 80% Samsung devices.
Affected 78% Android 13

A simplified Stack trace:
#01 Firebase.App.cpp:? (Not clear if this is important)
#02 NativeApi_UnityARCore_session_reset_m
#03 Unity.XR.ARCore.cpp:?
#04 2tvs_utils0.lump.cpp:?
#05 ARCoreProvider_Reset_m
#06 ARSession_Reset_m
#07 UnityEngine.UIElementsModule7.cpp:?
#08 UnityEngine.UIElementsModule7.cpp:?
#09 SC_AR_CloseAR_m (Our close function attached to a UI button)

 

That's the top of your crash callstack; it seems extremely important

"Firebase" is a Google SDK. Do you have the source to, or know where in,

Firebase.App.cpp

you are crashing? What is the crash reason, e.g., null pointer? jump to address 0x0?

 

@andyb-unity

Hi Andy, Before closing our AR scene we loop through all the Trackable planes and delete them, we used to have an issue with un-interactive planes remaining in the scene if the user reloaded into the AR scene. We have removed this loop and just call .Reset() on the ArSession, this appears to be functional in testing, so we will push this change to production and see if this remedies the crash. Thanks for your feedback.

@mekin I'm sure its important, but I was wondering if its the top of the stack because Firebase Crashlytics caught and reported the crash. As for the specific error, there is no detailed info in the crash, SIGSEGV title and an un-symbolicated stack, I used address-2-line and my symbols file to get the stack trace above. I don't know why we no longer get a proper crash and tombstone text file