When I'm opening my CMakeLists.txt I see that clion tries to generate a Debug, Release, RelWithDebInfo, MinSizeRel. Normally this would probably not be a big problem, but in my case it cause a problem since my CMakeLists.txt tries to populate the CMAKE_PREFIX_PATH with precompiled binaries. It seems to me that the CLion tries to generate all of these in parallel, causing them to race (I could be wrong).
Personally I never toggle the build type, and I could live with the extra few seconds delay regenerating it _if_ I wanted to switch project type.
I've tried to look in the settings, but I can't seem to find a way to disable/delete all of the other build types than "debug"...