How to manually add symbol files to GDB for debugging:

Symbol files are almost required because they translate meaningless addresses from a core dump to symbolic names, such as function names etc. They also help point you to the exact location in your source code where the exception occurred.

Step 1.

Once inside GDB at the command line, simply run:

(gdb) add-symbol-file /Path/To/Sym/Application.app.dSYM