App Crashes without going through my code

Question

While analyzing our crash logs I discovered that a fairly common crash is one that does not even occur in one of my own classes. These are external crash logs and I can't therefore not reproduce the problem.

Since I can't debug the Framework I am wondering, what a practicable approach could be to tackle this issue.

The only clue I have is that SIGSEGV might be a segmentation fault or an invalid pointer. But like I said since my Classes do not seem to be directly involved this does not help me much.

The Crash:

Exception Type:  SIGSEGV
Exception Codes: SEGV_ACCERR at 0x6b636f6c
Crashed Thread:  0

Thread 0 Crashed:
0   libobjc.A.dylib                     0x365c7f94 objc_msgSend + 43
1   CoreFoundation                      0x31cd23fd -[NSObject performSelector:withObject:withObject:] + 52
2   UIKit                               0x3291cfaf -[UIApplication sendAction:to:from:forEvent:] + 62
3   UIKit                               0x3291cf6b -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 30
4   UIKit                               0x3291cf49 -[UIControl sendAction:to:forEvent:] + 44
5   UIKit                               0x3291ccb9 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 492
6   UIKit                               0x3291d5f1 -[UIControl touchesEnded:withEvent:] + 476
7   UIKit                               0x3291bad3 -[UIWindow _sendTouchesForEvent:] + 318
8   UIKit                               0x3291b4c1 -[UIWindow sendEvent:] + 380
9   UIKit                               0x3290183d -[UIApplication sendEvent:] + 356
10  UIKit                               0x329010e3 _UIApplicationHandleEvent + 5826
11  GraphicsServices                    0x3572d22b PurpleEventCallback + 882
12  CoreFoundation                      0x31d4c523 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 38
13  CoreFoundation                      0x31d4c4c5 __CFRunLoopDoSource1 + 140
14  CoreFoundation                      0x31d4b313 __CFRunLoopRun + 1370
15  CoreFoundation                      0x31cce4a5 CFRunLoopRunSpecific + 300
16  CoreFoundation                      0x31cce36d CFRunLoopRunInMode + 104
17  GraphicsServices                    0x3572c439 GSEventRunModal + 136
18  UIKit                               0x3292fe7d UIApplicationMain + 1080
19  MyApp                               0x0000321f main (main.m:14)

Answer 1

This crash is likely a result of an error on your part. If you look at few of lines at the top of the stack trace it should give you a hint as to what is wrong.

1   CoreFoundation   0x31cd23fd -[NSObject performSelector:withObject:withObject:] + 52
2   UIKit            0x3291cfaf -[UIApplication sendAction:to:from:forEvent:] + 62
3   UIKit            0x3291cf6b -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 30
4   UIKit            0x3291cf49 -[UIControl sendAction:to:forEvent:] + 44

It looks like somewhere you have an object (possibly a view controller) that is registered for events but is deallocated too soon. The best thing to do is try to reproduce this while attached to the debugger. Start by checking code that handles UIControl callbacks such as UIButtons.