[Pre-RFC] `std` aware Cargo

[bitshiftmask]

Hey all,

After the Rust All Hands, I’ve put together a pre-RFC for a std aware Cargo. I’ve made a PR in a fork of the rust-lang/rfcs repo, and I hope to gather feedback before submitting this upstream.

This would allow users to rebuild or customize elements of core or std for custom targets, or targets where tweaks of these components are desired or needed.

Here is the PR where comments are welcome: PR Link, and here is the rendered version, for reading: Rendered Link.

I’m happy to answer any questions (on the PR link, please!). Feedback posted here is welcome, but will NOT be considered for my pre-RFC.

[steveklabnik]

I’m psyched about this!

I haven’t had time to fully digest this, but the thought of “stable features” was a gut negative reaction to me. But I think what you mean is that std etc gain cargo features, which then can be used like any other, right? That seems very normal, rather than the nightly-only stuff we use today. Maybe some wording clarifications here can help make that more clear.

[elichai2]

That sound awesome!

[mark-i-m]

This was the #1 thing on my Rust2019 wishlist. Thank you (x1000000)