Magic for your main.m to force exception logging.

gistfile1.m

static void uncaughtExceptionHandler(NSException *exception) {
  NSLog(@"EXCEPTION: %@", exception);
  NSLog(@"Stack trace: %@", [exception callStackSymbols]);
}

int main(int argc, char *argv[]) {
  NSSetUncaughtExceptionHandler(&uncaughtExceptionHandler);
  @autoreleasepool {
      return UIApplicationMain(argc, argv, nil, NSStringFromClass([MyAppDelegate class]));
  }
}