CMake: adding second build with other kit does not work

Creator creates CMake bases projects whithout problems when no CMakeLists.txt.user exists.

But adding a new kit (which works when used as first kit) gives an error about missing compiler:

CMake Error: your CXX compiler: "CMAKE_CXX_COMPILER-NOTFOUND" was not found.  
Please set CMAKE_CXX_COMPILER to a valid compiler path or name.

Looks like the environment related to the kit is not set.