How to set debug mode only in QtCreator?

Question

When Qt builds my project, it tries to do it both in the debug and release modes. However, I'm using an external library which I only have in debug mode. I'd like then to prevent QtCreator from building my project in the release mode so I won't have problems with the linker (I'm having problems with redefinitions when using "mixed-mode" libraries)

Answer 1

Go to project->Build Configurations and next to the pulldown menu with "Debug" and "Release" press "remove" when you have the "Release" configuration selected.

Why not just not select Release, and just build in Debug mode?