lints workflow : msrv sometimes needs a crate directory

[huitseeker]

Because those repos contain multiple crates we want to check the msrv for, they need a custom msrv job that cds into the crate's root directory:

• https://github.com/lurk-lab/bellpepper-gadgets
• https://github.com/lurk-lab/bellpepper

This makes the msrv step in the linting job from this repository unusable.

See lurk-lab/bellpepper-gadgets#13
See also #7, more specifically the suggestion of a crate parameter.

[samuelburnham]

foresterre/cargo-msrv#882 added workspace support, which is released in cargo-msrv 0.16.0-beta.20, but when I tested cargo msrv verify it returned an empty output.

I still think it's worth waiting a few weeks/months for workspace support to land on a stable release, and use custom MSRV workflows for workspaces like https://github.com/lurk-lab/bellpepper-gadgets/blob/main/.github/workflows/rust.yml#L77 until then.