It's used only as a dev dependency in 6 crates.

Depender (with downloads and own rev deps) build-context version
7.3M 210 portable-atomic dev ^0.1
1.4M 22 portable-atomic-util dev ^0.1
320K 15 cargo-config2 dev ^0.1
20K cargo-hack dev ^0.1
8.0K 1 atomic-maybe-uninit dev ^0.1
atomic-memcpy dev ^0.1