this was the answer from the brad larson on this SO question
If you add two breakpoints, you should be able to debug these exceptions. To do this, go to Run | Show |
I think Brad's answer is pretty clear; hopefully this can help if you're not finding it clear.
In Xcode, from the top menu click on Run > Show > Breakpoints. A new window pops up.
Select "global breakpoints" in the left hand menu. There should be a box on the right under the "Breakpoint" column with the text "Double-Click for symbol". Single-click in this box and type in "objc_exception_throw".
Then, single-click in the space next to "objc_exception_throw" under the "location" column. A box will appear for you to type in the location (in this case, "libobjc.A.dylib"). I've made a screenshot that will hopefully help:
I would also like to recommend adding the +[NSException raise:format:arguments:]
breakpoint and its location should be CoreFoundation
.
In Xcode 4 this great breakpoint can be added via "+" button on Breakpoints section (⌘ + 6)
in Xcode 6 -- from top menu
Debug > Breakpoints > Create Exception Breakpoint