many_cpus is used at run time in 3 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) many_cpus version
400 many_cpus_benchmarking ^0.0.1
230 region_cached ^0.0.1
230 region_local ^0.0.1
300 linked dev ^0.0.1