Git as a backup solution

I've seen a few things out there that permits the use of Git as a backup system...

The only one that seems to 'really' be able to store everything in a Git repository is 'gibak', implemented in Ocaml...

Others seem to mostly fit the note, except for the fact that they cannot store .git directories (kind of important for a 'generic' backup solution)....
It'd be interesting to see what a backup solution could
do WRT taking advantage of a given .git repository in packing even better by doing something like taking a stash of the current state of a git workspace + other files not being tracked by it for smaller packs.........

Are there any others out there?