Updating package rust-version to the latest version

[aksh1618]

TL;DR: Is upgrading package.rust-version within the scope of this project?

As a beginner in rust I like enabling lints to get used to idioms and avoid anti-patterns. Recently while working on a project (binary, not lib), I happened upon the use Trait as _ idiom which I decided to enforce. However the corresponding lint was only added in v1.83.

I have a function in my shell config that uses cargo-edit to upgrade all dependency crates in the current project to their latest versions. I decided to add a step to that function for upgrading the package.rust-version property to the latest stable version of rust. Looking at the help output of cargo-edit, it seemed like --rust-version was exactly what I was looking for, but looks like that's not the case:

# Update package.rust-version to latest stable version of rust
rustup update && cargo upgrade --rust-version `{rustc --version | cut -d " " -f2}` --compatible ignore # Doesn't modify cargo.toml

So I want to initiate a discussion on whether that's something this project would consider supporting.

[epage]

We wouldn't want to do this by default as there is a wide variety of opinions on this. I also suspect there isn't much value-add to automating this as its just a single-field to set. Even in workspaces, you can put the field in one location and then inherit it.

The MSRV resolver RFC does include approval for a rust-version = "<tbd-name-representing-currently-running-rust-toolchain>. I suspect we will wait a bit for the MSRV resolver to be out before we move forward with it. See https://rust-lang.github.io/rfcs/3537-msrv-resolver.html#cargo-publish