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

Depender (with downloads and own rev deps) build-context version
9.5M 201 portable-atomic dev ^0.1
2.3M 21 portable-atomic-util dev ^0.1
305K 13 cargo-config2 dev ^0.1
27K cargo-hack dev ^0.1
4.4K 1 atomic-maybe-uninit dev ^0.1
atomic-memcpy dev ^0.1