https://github.com/andrewchambers/bupstash#stability-and-bac...

> Bupstash is alpha software, while all efforts are made to keep bupstash bug free, we currently recommend using bupstash for making REDUNDANT backups where failure can be tolerated.

Interesting, I've been using bup[1] for years but it looks like bupstash is scratching the same itches I had.

[1]: https://github.com/bup/bup