No stack trace from NSAssert

Question

IIRC, this normally works. But recently I've noticed that NSAssert…() isn't giving me stack traces, or at least, not useful ones:

2012-02-26 14:41:19.283 MyApp[3299:707] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '…'
*** First throw call stack:
(0x33cc58bf 0x353e11e5 0x33cc57b9 0x317583b3 0x78423 0x76e35 0x77dbf 0x217dd 0x12c63 0x3178a943 0x33c99a63 0x33c996c9 0x33c9829f 0x33c1b4dd 0x33c1b3a5 0x3585bfcd 0x34d60743 0xde87 0x30dc)
terminate called throwing an exception(gdb) bt
#0  0x3629232c in __pthread_kill ()
#1  0x34b3ef5a in pthread_kill ()
#2  0x34b37fea in abort ()
#3  0x35fe9f6a in abort_message ()
#4  0x35fe734c in default_terminate ()
#5  0x353e12e2 in _objc_terminate ()
#6  0x35fe73c4 in safe_handler_caller ()
#7  0x35fe7450 in std::terminate ()
#8  0x35fe8824 in __cxa_rethrow ()
#9  0x353e1234 in objc_exception_rethrow ()
#10 0x33c1b544 in CFRunLoopRunSpecific ()
#11 0x33c1b3a4 in CFRunLoopRunInMode ()
#12 0x3585bfcc in GSEventRunModal ()
#13 0x34d60742 in UIApplicationMain ()
#14 0x0000de86 in main (argc=1, argv=0x2fdffaa4) at …/main.mm:18
(gdb) 

I read somewhere that using an iOS deployment target that Xcode doesn't have symbols for causes this, and I did change the setting recently from 4.0 to 4.3. However, changing it back makes no difference.

OTOH, assert(…) works as expected.

Why isn't Xcode providing a proper navigable stack trace when NSAssert…() fails?

Answer 1

I'm not sure why this is, but, if you set an exception breakpoint the breakpoint seems to stop execution early enough to see a useful backtrace. Once the breakpoint is hit bt in the console works as expected.

Make sure you don't check the "Automatically continue after evaluating" box. That seems to result in a useless backtrace like the one you posted.

You could also use NSSetUncaughtExceptionHandler() to set a logging callback function as described here.