>I've found it a really useful tool for installing things like Rust or Deno.

For Rust you can ignore sh.rustup.rs and just download and set up rustup manually.

    CARGO_HOME="${CARGO_HOME:-$HOME/.cargo}"
    mkdir -p "$CARGO_HOME/bin"
    curl -Lo "$CARGO_HOME/bin/rustup" 'https://static.rust-lang.org/rustup/dist/x86_64-unknown-linux-gnu/rustup-init'
    chmod +x "$CARGO_HOME/bin/rustup"
    hash -r
    rustup set auto-self-update disable
    rustup set profile minimal
    rustup default stable
    rustup update --force
    rustup self update # Create hardlinks under $CARGO_HOME/bin/