ArFragment leaking after parent activity finished

[0xGuybrush]

Issue

I was trying to track down a memory leak with ArFragment in my app so I created a minimal, complete, verifiable example here (Git repo).

It looks like with no other code installed, ArFragment is still leaking when its parent activity is closed.

Symptoms

Leak Canary is just showing:

GC Root: global variable in native code

I've examined the hprof file (zipped, attached here) and it seems like there's still a reference to the Fragment in its Scene's onUpdateListeners and onPeekTouchListeners:

But I may not be reading that accurately — Do we need to do additional tear-down for the ArFragment before exiting the activity? Referencing the sample code here, it doesn't look like I'm missing anything else & I've literally stripped out all other interaction with the fragment apart from resuming/pausing it.

Context

Dependencies

Using:

implementation 'com.google.ar:core:1.16.0'
implementation 'com.google.ar.sceneform.ux:sceneform-ux:1.15.0'
implementation 'com.google.ar.sceneform:core:1.15.0'

But was also occuring with AR Core 1.15.0

Device

I'm seeing this on Android 10 / Nokia 8.1

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Please let me know if you need more info.