Launching `rustup` from `Command` does not return a colored output

[Luni-4]

Problem you are trying to solve

When I run this command:

Command::new("rustup")
        .args(["target", "add", target])
        .output()
        .expect("Failed to run rustup");

I cannot get a colored text as output. It does not happen when I run the same command directly from my terminal.

Solution you'd like

Would it be possible to add a --color option even for the rustup installer? Thanks in advance!

Notes

No response

[rami3l]

Most CLI apps detect whether they are running in a TTY environment and, if not, the output won't be colorized.

OTOH, it's definitely possible to force colorized output, but indeed this doesn't seem to be implemented in rustup.

cargo has CARGO_TERM_COLOR=always to do this, so I imagine a similar option can be added to rustup?

[rami3l]

As a workaround: if you only want to run a subprocess with Rust while maintaining colored output, it's probably better not to capture the output and get the exit code only.

[rbtcollins]

I'm open to the idea of a variable forcing colorisation.

I would rather that we implemented a programmatic interface (something that doesn't exist at all today) and then pushed IDE integration and other wrapping code to use that and do their own UX.

[Luni-4]

Thanks a lot for implementing this feature! Could you please explain somewhere how to use that?

[rami3l]

@Luni-4 Just run with the environment variable RUSTUP_TERM_COLOR=always.