`cargo fetch` documentation endorses third-party, unmaintained `cargo prefetch` command

[briansmith]

Problem

From https://doc.rust-lang.org/cargo/commands/cargo-fetch.html as of today:

See also the cargo-prefetch plugin which adds a command to download popular crates. This may be useful if you plan to use Cargo without a network with the --offline flag.

Neither the crate on crates.io nor the GitHub repository have been updated for 7 years. I think it is safe to say that it is unmaintained. I think Cargo's documentation shouldn't be recommending unmaintained things.

Further, even if it were being actively maintained, I am not sure the recommendation makes sense, for a variety of reasons. Today, would we accept a PR that adds this recommendation? Probably not.

[epage]

This is being discussed in #16568

Neither the crate on crates.io nor the GitHub repository have been updated for 7 years. I think it is safe to say that it is unmaintained.

Lack of updates does not mean unmaintained.

From the maintainer at #16568 (comment)

However, can you say what the issue with it may be? AFAIK, it should still be working

Further, even if it were being actively maintained, I am not sure the recommendation makes sense, for a variety of reasons. Today, would we accept a PR that adds this recommendation? Probably not.

From me at #16568 (comment)

Some times the Cargo team needs to experiment and advertise the experiment to see what would be useful, so going purely off of download counts won't always be applicable.

In this case, this has been a while and ehuss mentioned it hasn't had much use. I can go either way.

[briansmith]

From me at #16568 (comment)

Some times the Cargo team needs to experiment and advertise the experiment to see what would be useful, so going purely off of download counts won't always be applicable.

I do agree with that. I would say that the informality of informal recommendations should be emphasized, and the experimental nature of experiments should similarly be emphasied, much like experimental language/library features are called out as such. Those call-outs are lacking here. Not just for CYA, but also because it is confusing for users to understand what is normative and non-normative text in the documentation.

[briansmith]

More motivation: The crate doesn't support the --locked option to get a reproducable-ish result.

$ cargo +nightly install -Z unstable-options --dry-run --locked cargo-prefetch
[snip]
warning: no Cargo.lock file published in cargo-prefetch v0.1.0