Nushell environment script (env.nu) is using the wrong string #4242

Verification

• I searched for recent similar issues at https://github.com/rust-lang/rustup/issues?q=is%3Aissue+is%3Aopen%2Cclosed and found no duplicates.
• I am on the latest version of Rustup according to https://github.com/rust-lang/rustup/tags and am still able to reproduce my issue.

Problem

I just installed rustup via curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

I use nushell, so when I next opened nushell it was very broken and both nushell/env.nu and nushell/config.nu contained source "$HOME/.cargo/env.nu

I fixed this with a source ~/.cargo/env.nu. You could equally use something like source ($nu.home-path | join .cargo/env.nu)`

cargo still couldn't be found, and I noticed the .cargo/env.nu was this:

if ("$HOME/.cargo/bin" not-in ($env.Path | split row (char esep))) {
  $env.Path = ($env.Path | prepend "$HOME/.cargo/bin")
}

Which resulted in a path of PATH=/home/user/$HOME/.cargo/bin:/home/user/.local/bin: ...

I haven't investigated what has caused this yet, but I would be happy to do so a bit later

Steps

1. Prepare a system with nushell but not cargo
2. Install cargo via rustip (curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh)
3. Open nushell and observe its errors

Possible Solution(s)

I assume some string interpolation has changed somewhere?

Notes

No response

Rustup version

rustup 1.28.1 (f9edccde0 2025-03-05)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.87.0-nightly (b74da9613 2025-03-06)`

Installed toolchains

Default host: x86_64-unknown-linux-gnu
rustup home:  /home/user/.rustup

installed toolchains
--------------------
nightly-x86_64-unknown-linux-gnu (active, default)

active toolchain
----------------
name: nightly-x86_64-unknown-linux-gnu
active because: it's the default toolchain
installed targets:
  x86_64-unknown-linux-gnu

OS version

ubuntu 24.04