问题
I have an app that runs fine on iOS, but when running with catalyst, it gives me this crash intermittently if I swipe to another virtual Desktop on macOS, and then back, for about 10 times. It mostly happens on a UICollectionViewController
This is the backtrace:
(lldb) bt
* thread #5, queue = 'com.apple.xpc.activity.com.apple.cloudkit.scheduler.com.apple.coredata.cloudkit.activity.export', stop reason = EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
* frame #0: 0x00007fff68c373ae libxpc.dylib`___xpc_activity_dispatch_block_invoke.107.cold.3 + 19
frame #1: 0x00007fff68c1ecdb libxpc.dylib`___xpc_activity_dispatch_block_invoke.107 + 746
frame #2: 0x00000001010377b3 libdispatch.dylib`_dispatch_call_block_and_release + 12
frame #3: 0x000000010103878f libdispatch.dylib`_dispatch_client_callout + 8
frame #4: 0x000000010103fd31 libdispatch.dylib`_dispatch_lane_serial_drain + 777
frame #5: 0x0000000101040ae8 libdispatch.dylib`_dispatch_lane_invoke + 438
frame #6: 0x000000010104df2e libdispatch.dylib`_dispatch_workloop_worker_thread + 681
frame #7: 0x00000001010c4053 libsystem_pthread.dylib`_pthread_wqthread + 290
frame #8: 0x00000001010c3eb3 libsystem_pthread.dylib`start_wqthread + 15
(lldb)
I have tried reviewing the codes, adding print statements, adding breakpoints, commenting out certain parts etc, trying to figure out which part of my code causes this, but failed so far.
I am using NSPersistentCloudKitContainer from iOS 13. Does the stack trace points to a bug inside there?
回答1:
I've wasted so much time trying to understand the source of the problem and hope that this answer helps many others.
This problems seems to persist now since a long time and has not been fixed, nor understood. But the big hint I've read in the comments: This crash happens only when the app is run from within Xcode.
Another important hint: You can can run your build product directly from Finder without crashing. Even if it is a "Debug" build.
Based on this, I've come to the conclusion that the problem is related to the Debug execution environment and I found the solution: Disable "Debug XPC services used by this application"
There must be some bug in the debugging code used by this option.
You can find this option in your targets scheme.
- Click on your target in the window bar
- Select "Edit Scheme..."
- Make sure "Run" is selected and remove the checkmark for "Debug XPC services used by this application"
I hope this helps everybody!
来源：https://stackoverflow.com/questions/58758353/exc-bad-instruction-from-com-apple-xpc-activity-com-apple-cloudkit-scheduler-com