I'm trying to diagnose a crash we're seeing in an app that's on TestFlight at the moment. We have the background location permission and are woken by various events, e.g. the significant location change event. I believe the app is being woken in the background and within a few seconds (about 7s in the example below) the app crashes. The crash appears to be when we are confirming what location authorisation the app currently has. As far as we know this is only happening for a single user. Any thoughts on what could be happening? Other forum posts led me to believe it was related to leaking background tasks but I didn't think that was likely after only 7s (and there's no actual mention of background tasks in the crash). Other threads in the crash log have core data relate tasks going on and while we've done a lot of work on our multi-threaded core data I could imagine that being a cause, but surely that would show as a crash on the threads involved rather than thread 0? Any help appreciated, crash log below. John AppVariant: 1:iPhone9,3:15 Beta: YES Code Type: ARM-64 (Native) Role: Non UI Parent Process: launchd [1] Date/Time: 2021-12-13 10:31:18.0065 +0000 Launch Time: 2021-12-13 10:31:11.4169 +0000 OS Version: iPhone OS 15.1 (19B74) Release Type: User Baseband Version: 6.00.00 Report Version: 104 Exception Type: EXC_CRASH (SIGKILL) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY Triggered by Thread: 0 Thread 0 name: Thread 0 Crashed: 0 libsystem_kernel.dylib 0x00000001bdd7cb10 mach_msg_trap + 8 1 libsystem_kernel.dylib 0x00000001bdd7d134 mach_msg + 72 (mach_msg.c:119) 2 libdispatch.dylib 0x0000000183f9c734 _dispatch_mach_send_and_wait_for_reply + 504 (mach.c:815) 3 libdispatch.dylib 0x0000000183f9caec dispatch_mach_send_with_result_and_wait_for_reply$VARIANT$mp + 52 (mach.c:2019) 4 libxpc.dylib 0x00000001de30f458 xpc_connection_send_message_with_reply_sync + 236 (connection.c:974) 5 Foundation 0x0000000185a0387c __NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY__ + 12 (NSXPCConnection.m:223) 6 Foundation 0x0000000185a09194 -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] + 2368 (NSXPCConnection.m:1649) 7 Foundation 0x0000000185a49f8c -[NSXPCConnection _sendSelector:withProxy:arg1:arg2:arg3:] + 148 (NSXPCConnection.m:1294) 8 Foundation 0x00000001859ece6c _NSXPCDistantObjectSimpleMessageSend3 + 80 (NSXPCDistantObject.m:282) 9 CoreLocation 0x000000018b0bba0c -[CLLocationInternalClient getAuthorizationStatus:forBundleID:orBundlePath:] + 140 (LocationInternal.m:786) 10 CoreLocation 0x000000018b0ba1fc CLInternalGetAuthorizationStatus + 268 (LocationInternal.m:2063) 11 CoreLocation 0x000000018b0df1c4 +[CLLocationManager _authorizationStatusForBundleIdentifier:bundle:] + 80 (CLClient.mm:1391)

I'm building a binary framework in Xcode 13.1 and expecting it to work in Xcode 12.5.1. I have BUILD_LIBRARY_FOR_DISTRIBUTION=Yes but the generated swift interface still references the Concurrency library (as import _Concurrency) because my framework contains UIViewController instances (and iOS 15 SDK now marks these with MainActor). Is there a way to build the framework so it's actually compatible with Xcode 12, have I missed some settings? As an example, the generated swift interface contains: ... import _Concurrency ... @objc @objcMembers @_Concurrency.MainActor(unsafe) public class MyViewController : UIKit.UIViewController { Any help appreciated. John