rustup component remove component-NOT-TOOLCHAIN-TARGET errors

[kadiwa4]

Problem you are trying to solve

I ran rustup component list --installed and saw that I had the component rust-std-wasm32-unknown-unknown installed, which I wanted to delete. I thought that I could simply copy-paste the component name into the remove command like this:

rustup component remove rust-std-wasm32-unknown-unknown

However, this doesn't work with remove. I got the following unhelpful error message:

error: toolchain 'nightly-x86_64-apple-darwin' does not contain component 'rust-std-wasm32-unknown-unknown' for target 'x86_64-apple-darwin'
note: not all platforms have the standard library pre-compiled: https://doc.rust-lang.org/nightly/rustc/platform-support.html
help: consider using `cargo build -Z build-std` instead

(Also the last line doesn't make sense because I'm trying to uninstall something here, not install it.)

Solution you'd like

The command that actually works is:

rustup component remove --target wasm32-unknown-unknown rust-std

I would like it if rustup told me that. You could assume that the component names which are output by list can also be passed back into rustup as a component name.

Notes

Version 1.25.1

[rbtcollins]

hmm so I totally agree with the motivation here; a path to fixing it would be to parse the target from the output, and infer target when not supplied.

[SummerGram]

Is there a rule to infer the target from the list?

@rustbot claim

[SummerGram]

@rbtcollins ,

In the component remove function, it is supposed to handle rust-docs-x86_64-apple-darwin this case with function called Component::new_with_target. But in that function, it fails to identify the target from rust-docs-x86_64-apple-darwin and rust-std-wasm32-unknown-unknown.

[SummerGram]

home/bin/rustup component remove clippy rustfmt-x86_64-apple-darwin rust-docs-x86_64-apple-darwin rust-std-wasm32-unknown-unknown

Component { pkg: "clippy", target: Some(TargetTriple("x86_64-apple-darwin")), is_extension: true }
"rustfmt" "x86_64-apple-darwin"
"rustfmt" "x86_64-apple-darwin" PartialTargetTriple { arch: Some("x86_64"), os: Some("apple-darwin"), env: None }
"rustfmt-x86_64" "apple-darwin"
"rustfmt-x86_64" "apple-darwin" PartialTargetTriple { arch: None, os: Some("apple-darwin"), env: None }
"rustfmt-x86_64-apple" "darwin"
Component { pkg: "rustfmt-x86_64-apple-darwin", target: Some(TargetTriple("x86_64-apple-darwin")), is_extension: true }
"rust" "docs-x86_64-apple-darwin"
"rust-docs" "x86_64-apple-darwin"
"rust-docs" "x86_64-apple-darwin" PartialTargetTriple { arch: Some("x86_64"), os: Some("apple-darwin"), env: None }
"rust-docs-x86_64" "apple-darwin"
"rust-docs-x86_64" "apple-darwin" PartialTargetTriple { arch: None, os: Some("apple-darwin"), env: None }
"rust-docs-x86_64-apple" "darwin"
Component { pkg: "rust-docs-x86_64-apple-darwin", target: Some(TargetTriple("x86_64-apple-darwin")), is_extension: true }
"rust" "std-wasm32-unknown-unknown"
"rust-std" "wasm32-unknown-unknown"
"rust-std-wasm32" "unknown-unknown"
"rust-std-wasm32-unknown" "unknown"
Component { pkg: "rust-std-wasm32-unknown-unknown", target: Some(TargetTriple("x86_64-apple-darwin")), is_extension: true }

[cyqsimon]

Ran into the same thing; was very confused.