[SentryFramesTracker removeListener:] crash

[SebastianKumor-Oura]

Platform

iOS

Environment

TestFlight

Installed

Swift Package Manager

Version

8.57.0 and 8.56.0

Xcode Version

26.0.1

Did it work on previous versions?

Not sure, only enabled frozen frames tracking recently

Steps to Reproduce

It happens randomly. I cannot easily reproduce this. And I think its related to enableUIViewControllerTracing setting being set to true

Expected Result

It should not cause crash

Actual Result

For some users app crashes sometimes.

Are you willing to submit a PR?

No response

[linear[bot]]

COCOA-869

[philipphofmann]

Thanks for reporting this, @SebastianKumor-Oura. I found a potential root cause

We use a lock for removing all objects of the listeners here https://github.com/getsentry/sentry-cocoa/blob/45e9fb14f5094d84db2d37539834b97ed4d6e687/Sources/Swift/Core/Integrations/FramesTracking/SentryFramesTracker.swift#L117-L119

Here we don't use locks but instead add and remove listeners on the main thread

https://github.com/getsentry/sentry-cocoa/blob/45e9fb14f5094d84db2d37539834b97ed4d6e687/Sources/Swift/Core/Integrations/FramesTracking/SentryFramesTracker.swift#L162-L172

[SebastianKumor-Oura]

@philipphofmann thanks for a quick response. Do you have any plans to address this issue ?

[philipphofmann]

@SebastianKumor-Oura, sorry no we don't have an ETA, but we're are going to fix the root cause at some point.

[GianmarcoSalerno]

I am still seeing this in 9.x btw....

[philipphofmann]

Thanks for the info @GianmarcoSalerno.