libmount is used at run time in 4 crates (of which 2 optionally). It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps) libmount version
23K sccache optional ^0.1.15
lithos ^0.1.10
libstratis ^0.1.9
rstash optional ^0.1.15
1 btrfsutil dev ^0.1.11
1 btrfsutil-fake dev ^0.1.11