Comment by IshKebab

That would be very easy to do with FUSE. I would be amazed if it hasn't been done.

I doubt it's really that useful though - it would be difficult to make the filesystem mutable, which means anything that puts caches or build files in the tree (which is most things) wouldn't work.

I did a very quick search. First result: https://github.com/csutorasa/git-fuse