When I run my app with XCode on my iPhone, and then moved into the background, I'm getting a EXC_BREAKPOINT exception after a few minutes, seemingly when iOS attempts to call my app with a BGAppRefreshTask:
Thread 23 Queue: com.apple.BGTaskScheduler (com.mycompany.MyApp.RefreshTask) (serial)
0 _dispatch_assert_queue_fail
12 _pthread_wqthread
Enqueued from com.apple.duet.activityscheduler.client.xpcqueue (Thread 23)
0 dispatch_async
20 start_wqthread
I can't quite understand the reason from this crash. In the background task, I'm attempting to update live activities. In the process, it might encounter code that calls MainActor and manipulate @Observable objects. Might that be the reason?