Which version of GDB?
Can you try and save the app first to a different folder?
But also, try this: In the Menu > Tools > Options > Debugger
There is a grid with options. It has:
EncodeCurrentDirPath = gdfeDefault
Try and set it to an other value, e.g. gdfeNone.
On Mac, the default is adjusted for the old gdb 6.3.50 (default = gdfeQuote)