mpsc is used at run time in 7 crates (of which 1 optionally).

Depender (with downloads and own rev deps) mpsc version
550 rsacracker ^0.2
460 1 task-exec-queue ^0.2
250 1 handy-grpc ^0.2
130 simln-lib ^0.2.0
emulatorr ^0.2.0
1 stdr ^0.2.0
500 rust-box optional ^0.2.4