At the moment I am editing CMakeCache.txt to set CMAKE_BUILD_TYPE:STRING=Debug but I would like to be able to switch from release to debug build within QtCreator.
The release build typically has no debug symbols, so theres not much use having QtCreator reference it at all, you can simply run the executable, its fast - use for testing optimizations or general usage.
The debug build is referenced from QtCreator and holds the project files.
If you really want, you could setup a separate project file in /src/cmake_release - then you would just open a different project to run the release build from QtCreator. (but both reference same source files)
@Marv - You can use ccmake, cmake-gui or edit CMakeCache.txt directly.
Maybe QtCreator can be setup to re-configure cmake, but not sure its worth it.
An advantage with this setup is you can switch the same CMake project to a different IDE without much trouble. Though so far I’ve not been that impressed by the alternatives.