In Xcode 4.x I\'ve edited my Run scheme to \'Enable Guard Malloc\' since I have a nondescript malloc error I need to track down. I\'m aware I need to run in the simulator to use
To help with the debugging you can set MallocStackLogging, then when your App crashes, type this in the gdb console:
(gdb) info malloc-history 0x543216
Replace 0x543216
with the address of the object that caused the crash, and you will get a much more useful stack trace and it should help you pinpoint the exact line in your code that is causing the problem.
See this article for more detailed instructions.