RUNNINGBOARD 0xdead10cc crash when inside a Notification Extension

[RamblinWreck77]

Mixpanel SDK: 4.1.0
Xcode: 14.3
iOS: Seems to happen on 16.0+

So we've been noticing a crash inside our notification service extension, which is very simple/only a few lines of code but it does setup the Mixpanel SDK in order to send events that the user has received a push notification successfully.

Looking into the stack trace this stood out:

Exception Type:  EXC_CRASH (SIGKILL)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Termination Reason: RUNNINGBOARD 0xdead10cc 

Triggered by Thread:  0


Thread 0 name:
Thread 0 Crashed:
0   libsystem_kernel.dylib        	0x00000001f8a73ff0 mach_msg2_trap + 8
1   libsystem_kernel.dylib        	0x00000001f8a85ad8 mach_msg2_internal + 76 (mach_msg.c:201)
2   libsystem_kernel.dylib        	0x00000001f8a85d78 mach_msg_overwrite + 484 (mach_msg.c:0)
3   libsystem_kernel.dylib        	0x00000001f8a744e4 mach_msg + 20 (mach_msg.c:323)
4   CoreFoundation                	0x00000001be2802b8 __CFRunLoopServiceMachPort + 156 (CFRunLoop.c:2622)
5   CoreFoundation                	0x00000001be281450 __CFRunLoopRun + 1208 (CFRunLoop.c:3005)
6   CoreFoundation                	0x00000001be285e90 CFRunLoopRunSpecific + 584 (CFRunLoop.c:3418)
7   Foundation                    	0x00000001b85f2218 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 208 (NSRunLoop.m:373)
8   Foundation                    	0x00000001b85f20c4 -[NSRunLoop(NSRunLoop) run] + 60 (NSRunLoop.m:398)
9   libxpc.dylib                  	0x0000000207f11840 _xpc_objc_main + 492 (main.m:246)
10  libxpc.dylib                  	0x0000000207f13968 xpc_main + 152 (init.c:1258)
11  Foundation                    	0x00000001b86358c4 -[NSXPCListener resume] + 260 (NSXPCListener.m:460)
12  PlugInKit                     	0x00000001e2255058 -[PKService run] + 328 (PKService.m:197)
13  PlugInKit                     	0x00000001e2242998 +[PKService main] + 532 (PKService.m:119)
14  PlugInKit                     	0x00000001e2241d44 +[PKService _defaultRun:arguments:] + 12 (PKService.m:244)
15  ExtensionFoundation           	0x00000001cab0fca0 EXExtensionMain + 248 (EXExtensionMain.m:34)
16  Foundation                    	0x00000001b8675858 NSExtensionMain + 176 (NSExtensionMain.m:14)
17  dyld                          	0x00000001db98b344 start + 1860 (dyldMain.cpp:1165)

Which lead me to here:

https://developer.apple.com/forums/thread/111259

The exception code

0xdead10cc
indicates that an application has been terminated by the OS because it held on to a file lock or sqlite database lock during suspension. If your application is performing operations on a locked file or sqlite database at suspension time, it must [request additional background execution time](https://developer.apple.com/reference/uikit/uiapplication/1623051-beginbackgroundtask) to complete those operations and relinquish the lock before suspending.“

Our app doesn't use sqlite at all, and we're down to just Mixpanel and Lottie as dependencies (Lottie is a UI animation library, so no sqlite there, also it's not imported/part of the notification extension) so I'm 99.9% sure it's in the Mixpanel SDK.

I've never heard a of crash like this (requiring you to release a lock on a resource before suspension, or crash?!), so it's possible this could be the root cause of a lot of "weird" crashes that are otherwise hard to pin down.

[RamblinWreck77]

Another useful thread:

https://developer.apple.com/forums/thread/126438

[RamblinWreck77]

Also, while this is happening for us inside a Notification Extension I don't see any reason why it would be limited to that.

[jaredmixpanel]

@RamblinWreck77 Hmm, first I've heard of it... not clear to me what the right approach is to prevent that exception. Any ideas?