How do I find out what exception was thrown in the Xcode debugger (for iPhone)?

Question

I\'m learning iPhone programming from Erica Sadun\'s The iPhone Developer\'s Cookbook. When I run the app I created by following the steps in the Temperature Conversion Exa

Answer 1

Put a breakpoint at objc_exception_throw and run your app via Debug instead of Run

To clarify, what you're actually seeing when you get an exception without the breakpoint is the same stack trace always - it's the uncaught exception handler. The type of exception is logged to the Run console, but if you want to see a backtrace for where the exception was raised, that's what the breakpoint is for.

Answer 2

As Kevin answered, you will find more helpful debugging info by setting a breakpoint at objc_exception_throw.

If you are using Xcode 4.2, you can add this symbolic breakpoint by going to Breakpoint Navigator > Click on the add icon on the bottom left > Add symbolic breakpoint > Enter objc_exception_throw for Symbol > Done.

Answer 3

http://ijoshsmith.com/2011/11/28/debugging-exceptions-in-xcode-4-2/

Same as samewize's solution, but also shows how to make this breakpoint show up by default in all your projects (right click on breakpoint, Move Breakpoint To, User).

Answer 4

In the new Xcode (at least starting from v4.5), you can catch all exceptions easily by doing this:

1. Bring up breakpoint navigator (⌘6)
2. Click + on the bottom left
3. Add Exception Breakpoint

I think the above is the same as a breakpoint on objc_exception_throw. http://samwize.com/2012/09/26/xcode-4-dot-5-tips-and-tricks/