What I mean is you listed the CMakeError.log file. During cmake configuration, it looks for how to do threading; some fail before cmake finds one that works. Cmake documents these errors in this file, and these errors are not abnormal ... they are just part of cmake doing its job.
That said, cmake's normal output printouts and other logging are only as good as it is programmed to do. GR does a pretty good job of showing what's going on so that one can figure out the issues & then how to resolve them. GR OOTs vary a lot in this regard.