On linux it's almost always better to use pkg-config, than to add the includes manually.
You can add the appropriate lines for compiler (and linker) to the other-options tabs (in backticks).
And is there a special cause, you added it for the debug-target?
Wouldn't it be better to use it for the whole project, so you do not need to add it twice (which is harder to maintain and probably error-prone) ?