1.28.0 does not accept components separated by spaces

[marmeladema]

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

Hello,

At work, we use

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path -y --default-toolchain nightly-2025-02-11 -c cargo rustc rust-src

to install a specific version of rust in our CI environment but since latest version (ie: v1.28.0), it fails with:

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path -y --default-toolchain nightly-2025-02-11 -c cargo rustc rust-src
info: downloading installer
error: error: unexpected argument 'rustc' found

Usage: rustup-init[EXE] [OPTIONS]

For more information, try '--help'.

After reading https://blog.rust-lang.org/2025/03/02/Rustup-1.28.0.html I understand that some amount of backward incompatible changes have been released (with very short notice) but I don't understand:

1. Why it impacts my current workflow since I am specifically asking for a toolchain
2. How to fix it. I am absolutely able to fix my CI configuration, but at the moment, I have no idea how and the error message doesn't provide any kind of help.

Thank you in advance for your help 👍

Steps

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path -y --default-toolchain nightly-2025-02-11 -c cargo rustc rust-src

Possible Solution(s)

No response

Notes

No response

Rustup version

1.28.0

Installed toolchains

nightly-2025-02-11

OS version

Linux

[marmeladema]

I tried changing my CI to:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path -y --default-toolchain none
source $HOME/.cargo/env
rustup toolchain install nightly-2025-02-11 -c cargo rustc rust-src

But the last command still fails with:

error: invalid value 'rustc' for '[TOOLCHAIN]...': invalid toolchain name: 'rustc'

[marmeladema]

I finally figured it out. The problem is that the new version of rustup expect a comma-separated list of components whereas before, a space separated list at the end of the command line worked. Here is the fix:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path -y --default-toolchain nightly-2025-02-11 -c cargo,rustc,rust-src

I guess this is just another breaking change, but I re-read multiple times https://blog.rust-lang.org/2025/03/02/Rustup-1.28.0.html and it is not announced anywhere?

[djc]

Ah yes, this is likely an artifact of our clap upgrade that might not have been as much of a conscious change. Thanks for figuring it out, we will check how to mitigate this.

[marmeladema]

@djc problem is resolved on my side but i'll leave it up to the rustup team to decide whether to close the issue or not.
The fix is easy, but not that easy to figure out so even if closed, a cheatsheet for common problems with 1.28.0 is probably helpful.

[lnicola]

We're also seeing some breakage for rustup component add --toolchain nightly rustfmt, but only on Windows:

error: invalid value 'C:\Users\runneradmin\.cargo\bin\rustup.exe' for '[+toolchain]': error: "C:\Users\runneradmin\.cargo\bin\rustup.exe" is not a valid subcommand, so it was interpreted as a toolchain name, but it is also invalid. To override the toolchain using the 'rustup +toolchain' syntax, make sure to prefix the toolchain override with a '+'

It's similar, but not the same as marmeladema's error from above.

EDIT: this fixed it:

-          rustup toolchain add nightly --profile minimal
-          rustup component add --toolchain nightly rustfmt
+          rustup toolchain install nightly --profile minimal --component rustfmt

[BenjaminBrienen]

Maybe rustup could have some pre-release tests in an action that run rustup.exe in various ways to make sure the CLI interface doesn't break.

[rami3l]

Probably related

• Cannot install toolchain if preceding option uses comma separated list as an argument #4073

[djc]

We're also seeing some breakage for rustup component add --toolchain nightly rustfmt, but only on Windows:

error: invalid value 'C:\Users\runneradmin\.cargo\bin\rustup.exe' for '[+toolchain]': error: "C:\Users\runneradmin\.cargo\bin\rustup.exe" is not a valid subcommand, so it was interpreted as a toolchain name, but it is also invalid. To override the toolchain using the 'rustup +toolchain' syntax, make sure to prefix the toolchain override with a '+'

It's similar, but not the same as marmeladema's error from above.

EDIT: this fixed it:

- rustup toolchain add nightly --profile minimal
- rustup component add --toolchain nightly rustfmt
+ rustup toolchain install nightly --profile minimal --component rustfmt

Should potentially file a separate issue for this -- edited the title for this issue to keep the scope narrow.

[rami3l]

I highly doubt whether we can fix this without regressing #4073, but if you can, using commas would be a better option for a quick fix.