C1083 on two compiler generated files when building from source

Which is not going to be easy, since I ultimately narrowed it down to the fact that my Windows install is configured for automatic cloud backup, and how the system handles that function in terms of storage management (which I had to override for continuous local availability, which will take a while to be in effect). As for the path issue, I did give thought to that, but it threw an error in the file explorer when I tried relative to storage space. In any case, I did set a symlink to another part of the file system (though it’s primarily for EGS detection, but it may also help with the other matters).