Running a git-based program (Bup) on Ubuntu WSL gives error “[Errno 38] Function not implemented”

My Ubuntu setup is running great and things to seem to be working well for other things I’m doing but with one particular program (Bup) which is a backup solution built on top of git.

Running this command gives the errors [Errno 38] Function not implemented

bup save -n InitialCommit /mnt/c/BackupTest 

From basic Googling it seems to be Python or git related and possibly related to multithreaded processing not being supported, but I’m not sure if that is what’s happening here.