One of my apps, that I develop started to crush every second time on simulator after I updated XCode Version 4.6.2 and OS X Mountain Lion (OS X 10.8.4). I couldn’t figure out why, because method didFinishLaunchingWithOptions didn’t even start when the crush occured. After some search in the web I found solution here and here.

These are instructions:
Open the menu Product -> Scheme -> Edit Scheme, select Run YouAppName.app on the left, tab Info. Then choose GDB instead of LLDB in debugger field.

The reason of this bug is probably:
The issue occurs to a process race condition for debugserver. Instead of using GDB, you can alternatively kill your execution, wait a few seconds for the app to wrap up, and then run the next iteration.