rustup-toolchain is used at run time in 1 crate. It's used only as a dev dependency in 4 crates.

Depender (with downloads and own rev deps) rustup-toolchain version
hax-subcommands ^0.1
147K 198 syntect dev ^0.1.5
1.7K cargo-public-api dev ^0.1.6
300 2 rustic_core dev ^0.1.6
1 organize-rs_core dev ^0.1.4