yes, lmdb-rkv at https://github.com/mozilla/lmdb-rs
Discussion
Was looking at that earlier today but was spooked by the issues mentioning iterator crashes 👀
Seems they've been around at least four years on this repo, and probably longer on the repo this was derived from. If you don't try to drop a cursor and keep using the iterator derived from it, you should be okay. Why they can't have rust enforce that ¯\_(ツ)_/¯