jobserver is used at run time in 166 crates (of which 15 optionally, 11 directly). It's used at build time in 1,186 crates (of which 335 optionally, 1 directly). It's used only as a dev dependency in 80 crates.

Depender (with downloads and own rev deps) jobserver version
2.0M 941 cc optional ^0.1.16
27K 80 cargo ^0.1.21
22K 18 rustc-ap-rustc_data_structures ^0.1.13
5.2K sccache ^0.1
3.9K 13 opencv build ^0.1
2.3K 1 build-parallel ^0.1.19
270 1 hal ^0.1.11
cargo-semverver ^0.1.11
5 cargo-util ^0.1.21
10 fast-rustc-ap-rustc_data_structures ^0.1.13
5 msiz_rustc-ap-rustc_data_structures ^0.1.13
vkcargo ^0.1.21