how to debug EXC_CRASH (SIGTRAP)

Question

i'm running my app are running fine until i resume from background or with out location services, the app will crash.

the crash log shows Exception Type: EXC_CRASH (SIGTRAP)

Anybody know how to debug it ?

Exception Type:  EXC_CRASH (SIGTRAP)
Exception Codes: 0x00000000, 0x00000000
Crashed Thread:  0

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   libsystem_kernel.dylib          0x36398848 __kill + 8
1   FrogFinder                      0x000b5034 0x69000 + 311348
2   CoreFoundation                  0x3447e980 __handleUncaughtException + 68
3   libobjc.A.dylib                 0x346ce2ca _objc_terminate + 122
4   libc++abi.dylib                 0x338a33be _ZL19safe_handler_callerPFvvE + 70
5   libc++abi.dylib                 0x338a344a std::terminate() + 14
6   libc++abi.dylib                 0x338a481e __cxa_rethrow + 82
7   libobjc.A.dylib                 0x346ce22e objc_exception_rethrow + 6
8   CoreFoundation                  0x343d453e CFRunLoopRunSpecific + 398
9   CoreFoundation                  0x343d439e CFRunLoopRunInMode + 98
10  GraphicsServices                0x30c58fc6 GSEventRunModal + 150
11  UIKit                           0x3785573c UIApplicationMain + 1084
12  FrogFinder                      0x0006a7e6 0x69000 + 6118
13  FrogFinder                      0x0006a7a4 0x69000 + 6052

Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0   libsystem_kernel.dylib          0x363893b4 kevent + 24
1   libdispatch.dylib               0x370b3e78 _dispatch_mgr_invoke + 708
2   libdispatch.dylib               0x370b3b96 _dispatch_mgr_thread + 30

Thread 2 name:  WebThread
Thread 2:
0   libsystem_kernel.dylib          0x36389010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x36389206 mach_msg + 50
2   CoreFoundation                  0x3445241c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x34451154 __CFRunLoopRun + 876
4   CoreFoundation                  0x343d44d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x343d439e CFRunLoopRunInMode + 98
6   WebCore                         0x368a8128 _ZL12RunWebThreadPv + 396
7   libsystem_c.dylib               0x33224c16 _pthread_start + 314
8   libsystem_c.dylib               0x33224ad0 thread_start + 0

Thread 3 name:  com.apple.NSURLConnectionLoader
Thread 3:
0   libsystem_kernel.dylib          0x36389010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x36389206 mach_msg + 50
2   CoreFoundation                  0x3445241c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x34451154 __CFRunLoopRun + 876
4   CoreFoundation                  0x343d44d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x343d439e CFRunLoopRunInMode + 98
6   Foundation                      0x35dd4bc2 +[NSURLConnection(Loader) _resourceLoadLoop:] + 302
7   Foundation                      0x35dd4a8a -[NSThread main] + 66
8   Foundation                      0x35e6859a __NSThread__main__ + 1042
9   libsystem_c.dylib               0x33224c16 _pthread_start + 314
10  libsystem_c.dylib               0x33224ad0 thread_start + 0

Thread 4:
0   libsystem_kernel.dylib          0x36389010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x36389206 mach_msg + 50
2   CoreFoundation                  0x3445241c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x34451154 __CFRunLoopRun + 876
4   CoreFoundation                  0x343d44d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x343d439e CFRunLoopRunInMode + 98
6   Foundation                      0x35dc8b7e -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 250
7   Foundation                      0x35de252c -[NSRunLoop(NSRunLoop) run] + 72
8   FrogFinder                      0x000c8da6 0x69000 + 392614
9   Foundation                      0x35dd4a8a -[NSThread main] + 66
10  Foundation                      0x35e6859a __NSThread__main__ + 1042
11  libsystem_c.dylib               0x33224c16 _pthread_start + 314
12  libsystem_c.dylib               0x33224ad0 thread_start + 0

Thread 5 name:  NetworkIO
Thread 5:
0   libsystem_kernel.dylib          0x36389010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x36389206 mach_msg + 50
2   CoreFoundation                  0x3445241c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x34451154 __CFRunLoopRun + 876
4   CoreFoundation                  0x343d44d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x343d439e CFRunLoopRunInMode + 98
6   MapKit                          0x38030412 0x38022000 + 58386
7   Foundation                      0x35dd4a8a -[NSThread main] + 66
8   Foundation                      0x35e6859a __NSThread__main__ + 1042
9   libsystem_c.dylib               0x33224c16 _pthread_start + 314
10  libsystem_c.dylib               0x33224ad0 thread_start + 0

I think you need to symbolicate this line : 1 FrogFinder 0x000b5034 0x69000 + 311348 to get the name of the crashing method. You can find informations on symbolicate here : http://stackoverflow.com/questions/1460892/symbolicating-iphone-app-crash-reports — Johnmph, Dec 22 '11 at 00:23
Did you solve this issue? If so, I would love to hear what caused the problem. This is an unusual error. — SAHM, Nov 04 '13 at 23:08

score 23 · Accepted Answer · answered Dec 22 '11 at 02:58

You can also turn on Exception breakpoints. In XCode 4 click your project and choose the breakpoints tab. At the bottom of that tab is | + | - | search bar. Choose the + item and "Add Exeception Breakpoint". You can leave it at All or choose Objective-C. This way you will break in the debugger and be able to see what caused the exeception.

score 9 · Answer 2 · answered Dec 22 '11 at 03:30

With Xcode 4.2 and iOS 5 uncaught exceptions do not seem to show in the console anymore. I would recommend adding the following or modifying your existing uncaught exception handler to dump the exceptions callstack for you.

#ifdef DEBUG
void eHandler(NSException *);

void eHandler(NSException *exception) {
    NSLog(@"%@", exception);
    NSLog(@"%@", [exception callStackSymbols]);
}
#endif

int main(int argc, char *argv[]) {

#ifdef DEBUG
    NSSetUncaughtExceptionHandler(&eHandler);
#endif

...rest of your main function here...

}

score 0 · Answer 3 · answered Jan 27 '20 at 06:19

The easiest way for this kind of crashes which are occuring during development is to add exception break points. You can add exception breakpoint like below

Select the break points option in left menu in XCode

Add the exception break point

Add breakpoint for all the exceptions

Run the app. In most of the cases when exception occurs XCode will stop the execution and show you the line which caused the exception.

how to debug EXC_CRASH (SIGTRAP)

3 Answers3

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