Investigate `rustup component` for `cargo-gpu`

[schell]

It would be great to be able to rustup component add spirv-builder-cli or something similar...

[LegNeato]

I was thinking maybe the opposite might be easier (as I bet the components come from a central rust project place we wouldn't have access to). To use rustup as a library, wrap it, or soft fork it. So all the plumbing and ux is taken care of for us and later going in rustup proper is easy.

[LegNeato]

Some docs I found:

https://forge.rust-lang.org/infra/channel-layout.html

[LegNeato]

Looks like RUSTUP_DIST_SERVER enables overriding where rustup looks. See also https://rust-lang.github.io/rustup/environment-variables.html

[schell]

Ok, I see. I think getting our own binary distribution service would be a better user experience, but that's quite a big lift. Also rustup is pretty large! It has a lot of commands and subcommands. I think we can get away with much less.

[LegNeato]

You might want to look into how rustc-perf uses it...the tool obviously doesn't expose all rustup but it uses the plumbing, which I think is roughly what we need (plus some special sauce on top). I also don't think we need a distribution service, I think we can use github releases or a static repo 🤷‍♂️

Maybe it is not the right solution, but I'd hate to roll and maintain our own if we can leverage what is there if at all possible.

[schell]

After looking at that, I think it would actually be more work to use the rustup machinery. All we need is a cache directory and some deterministic prefixes.

I'm still in favor of this if it turns out that the current solution is untenable, for whatever reason, but for now I think this is a non-issue.