Manifest issue with "preview" components

[mbrossard]

I was asked to file an issue following a Zulip question.

I was able to install the llvm-tools component. Following some confusion, it turns out that this should not work since it should only be installable as llvm-tools-preview.
Following some research, https://static.rust-lang.org/dist/2023-01-26/channel-rust-1.67.toml contains the following section (that https://static.rust-lang.org/dist/2022-12-15/channel-rust-1.66.toml did not):

[renames.llvm-tools]
to = "llvm-tools-preview"

I think the issue arose with a3dd94e and 494cb47 where I think there was a conflation of components that had preview status (needing a rename section) and components that currently have preview status (that should not have a rename). Looking at pkgtype! in https://github.com/rust-lang/rust/blob/master/src/tools/build-manifest/src/versions.rs#L41 there are I think two distinct groups of components with preview=true:

• rls, rust-analyzer, clippy and rustfmt which are stable (and probably were historically previews).
• llvm-tools, miri, rust-docs-json and rustc-codegen-cranelift which are not stable.

The main issue is that the components of the second group should currently only be added with their -preview suffix but currently can be added without the suffix.

[mbrossard]

@Mark-Simulacrum requested this issue to be labeled T-bootstrap + T-infra.

[thejpster]

Can be, and is:

https://github.com/search?q=%22rustup+component+add+llvm-tools+%22&type=code (plus a bunch more that are harder to search for because tools isn't followed by a space character)

I've certainly been using the 'new' name, thinking it had been stablised:

https://github.com/search?q=org%3ANeotron-Compute%20llvm-tools&type=code

[RalfJung]

For Miri, AFAIK it was intentional to make the component available as miri -- the key thing is that it only exists on nightly.