The C compiler doesn't change when choosing the compiler.

When choosing the compiler in the kit, only the C++ compiler is changed with -DCMAKE_CXX_COMPILER. The C compiler will instead use the system default. Additionally, the compiler only lets you choose the path to the C++ compiler (e.g. g++ or clang++) without any way to give the path to the C compiler. (e.g. gcc or clang)

For example, when trying to switch the compiler to clang, this is the output from cmake:

– The C compiler identification is GNU 6.1.1
– The CXX compiler identification is Clang 3.8.0
– Check for working C compiler: /usr/bin/cc
– Check for working C compiler: /usr/bin/cc – works
...
– Check for working CXX compiler: /usr/bin/clang++
– Check for working CXX compiler: /usr/bin/clang++ – works