Started from scratch by re-downloading the source and used the subst command to make a new path to build with.
Created a virtual drive to avoid the PATH length limit: subst a: .\qt-everywhere-src-6.6.2\ created the build folder and ran the configure.bat like the following: PS a:\build> ..\configure.batRan the command cmake --build . --parallel
Ran the install command afterwards
PS a:\build> cmake --build . --parallelNo issues and everything was installed.