Rust newbie question.
Raspberry Pi 4B, newly installed I added Rust, Rust documentation, debugger, etc. via Add/Remove Software. I checked /usr/bin and found cargo, rustc, rust-clang, rustdoc, rust-gdb, rust-lld, but not rustup. Since most everything I've referenced mentioned rustup, it seems important. If I install it with
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
will it coexist with the stuff installed earlier? Is rustup really needed if cargo is there?
You're probably using a packaged version of rustc. It likely won't be updated as frequently as the rustup versions would, but it will work just fine if that isn't important for your purposes.
If you install rustup, you should uninstall the packaged versions so there's no confusion about which version is being used.
Generally installing with rustup is preferred since rustup has a bunch of nice features, like making it easy to work with different versions of rustc across different projects.
Note also there is the middle ground of installing a packaged version of rustup (not downloading it from rustup.rs) and using that rustup to install rustc & cargo. This is usually just as good since rustup doesn't need to be updated regularly.