Okay, re-reading that, I take it that you mean the GMS2 Mac beta rather than the Mac target for GMS2 on Windows?
Should try on a blank project, but I'm not sure if the debugger is actually implemented in Mac beta yet - I remember reading that it was in the works because the original debugger would not function on Mac due to using too many Windows-specific features.
It should still log some information into the "compile form" though.
I'll try setting up the mac beta on the mac I have to investigate this when the time permits.