OnceMutex is used at run time in 44 crates (of which 12 optionally). It is a direct run-time dependency in 3 crates. It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps) OnceMutex version
202K 2 regex-cache ^0.1
140 2 kompact ^0.1
lazy *