It's a problem with either CMake or your compiler installation. You will get that error when trying to build any cmake project. I've had the error go away in the past after removing and reinstalling cmake and codeblocks (and rebooting). If I had to guess then I would say that the real issue is just that the location of the compiler which you are using isn't in your PATH environment variable (or that you have multiple gcc compilers in your PATH and it chooses the wrong one).