mpsc is used at run time in 6 crates (of which 2 optionally).

Depender (with downloads and own rev deps) mpsc version
650 1 task-exec-queue ^0.2
160 1 handy-grpc ^0.2
1 stdr ^0.2.0
emulatorr ^0.2.0
470 rust-box optional ^0.2.4
230 rsacracker optional ^0.2