How to track down cause of SIGABRT

Question

I\'m showing the code to this problem for example purposes, but really my question is: how am I supposed to track down and understand SIGABRT errors? I read this question:

Answer 1

SIGABRT rises when an object receives unimplemented message. How many warnings does your app have? Try surfing through them and find the ones that warn you "some object may not respond to some selector", if you clean your app from all of these, you'll most probably get it working correctly.

EDIT: Answer from comments below which are very helpful:

ok, here goes heavy artillery - have you tried using breakpoints? Open the sixth tab in your project explorer, in the bottom left corner tap + -> Add exception breakpoint -> Done. This will add an exception handler that will stop your app on the very method call that crashes the app.

EDIT: As of xCode 5.0 > You no longer need to specify which exception is your breakpoint is going to catch while the breakpoint is being created. You just need to hit + -> Add exception breakpoint and you're good.