Regardless of what "everybody assumes", you can in fact build rust binaries without using rustup or cargo. Distros do this. Yes, it's more painful for end users than just typing `cargo build`, but that's irrelevant to distro maintainers.

Some software (e.g. IDEs) will call `rustup` for some reason (yep, it happened to me and I therefore couldn't use that software).

> Yes, it's more painful for end users than just typing `cargo build`

Cargo is fine, I don't mind installing cargo. I just don't want my packages to be handled by my package manager. I don't want every project to ship their own custom package manager like rustup.