First, find the .octest file of interest: % find . -name "*.octest" -print ./build/Debug/Tests.octest Then gdb Tools/otest: % gdb /Developer/Tools/otest Then run it with the name of the bundle: (gdb) run ./build/Debug/Tests.octest
.octest
% find . -name "*.octest" -print ./build/Debug/Tests.octest
Tools/otest
% gdb /Developer/Tools/otest
(gdb) run ./build/Debug/Tests.octest