Stopping at breakpoints causing EXC_BAD_ACCESS
From what I can see, LLDB appears to be broken in the Xcode 4.2 and 4.2.1. Switch to GDB in your "Edit Scheme" settings.
Breakpoints work just as expected after switching to GDB.
To anyone that might experience the same thing with Xcode 5.0.1 and Mavericks:Try deleting all your schemes and auto create them again - that fixed it for me.
Where you using lldb instead of gdb ? I'm getting this systematically with Xcode 4.2.1 and lldb. Switching back to gdb (booooo) solves the problem.