Installing rust-docs during rustup is slow, particularly on Windows. This is a common occurrence on desktops due to Anti-Virus checks. I think we can significantly reduce the amount of build time by allowing to chose components for rustup. Preferable rust-docs would be disable by default, but users can choose to enable it.
Ah unfortunately rustup doesn’t allow installation of rustc without the rust-docs component just yet, so when using rustup there’s no way to not install rust-docs right now.
This is something the Rust community is looking to improve though!