We've been receiving crash reports with nearly identical stack traces from devices running beta versions of iOS 18.0 and 18.1.
The crash consistently occurs after app launch and the first call to a global function that uses withTaskCancellationHandler(operation:onCancel:isolation:). I'm surprised that the stack trace for the crash on iOS 18.1 also indicates the back-deployed thunk. I thought it made sense for older versions to show this crash but not for the newer one.
So far, we haven't been able to reproduce it ourselves unless we build the app for Mac (Designed for iPhone).
OS Version: iOS 18.1 (22B5007p)
Report Version: 104
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: SEGV_NOOP at 0x0000000000000004
Crashed Thread: 6
Application Specific Information:
Exception 1, Code 1, Subcode 4 >
KERN_INVALID_ADDRESS at 0x4.
Thread 6 Crashed:
0 NeoCore 0x106278cb8 $ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlFTwb
1 libswift_Concurrency.dylib 0x33c9c88d0 swift::runJobInEstablishedExecutorContext