Improve Rust installation with Python's rustup

[Tremeschin]

The bundled rustup isn't rustup-init that creates symlinks to the toolchain items. Rustup expects to be at CARGO_HOME:

❯ rustup install stable
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
  stable-x86_64-unknown-linux-gnu unchanged - rustc 1.87.0 (17067e9ac 2025-05-09)
error: rustup is not installed at '/home/tremeschin/.cargo'

I might take on #13 together and create a class to do this sort of automation. Arch package contains such links at /usr/bin/, there's a way around this to symlink ~/.cargo/bin/rustup to the venv's one, but should we do it in a separate Pyaket's CARGO_HOME (no)?

[Tremeschin]

Literally- what?

❯ sha256sum ~/Code/.venv/bin/rustup
20a06e644b0d9bd2fbdbfd52d42540bdde820ea7df86e92e533c073da0cdd43c  rustup

# From https://static.rust-lang.org/rustup/archive/1.28.2/x86_64-unknown-linux-gnu/rustup-init
❯ sha256sum rustup-init 
20a06e644b0d9bd2fbdbfd52d42540bdde820ea7df86e92e533c073da0cdd43c  rustup-init

❯ ./rustup
rustup 1.28.2 (e4f3ad6f8 2025-04-28)

The Rust toolchain installer

Usage: rustup[EXE] [OPTIONS] [+toolchain] [COMMAND]

❯ ./rustup-init 
Welcome to Rust!

This will download and install the official compiler for the Rust
programming language, and its package manager, Cargo.
...
1) Proceed with standard installation (default - just press enter)
2) Customize installation
3) Cancel installation

[Tremeschin]

Nice. (1) (2)

❯ cp rustup rustup-what
❯ ./rustup-what 
error: unknown proxy name: 'rustup-what'; valid proxy names are 'rustc', 'rustdoc',
'cargo', 'rust-lldb', 'rust-gdb', 'rust-gdbgui', 'rls',  'cargo-clippy',
'clippy-driver', 'cargo-miri', 'rust-analyzer', 'rustfmt', 'cargo-fmt'

I need a vision from the holy on what to make of this. I sleep.