Pre-RFC: Support package sets in cargo

[Ixrec]

There's a lot of prior discussion on this one, so lemme add what are imo the best recent threads:

Idea: introduce `project` field to Cargo.toml to make micro-crate designs less scary

In this discussion I've ended up with the following idea. I think it's worth to flesh out it a bit more and have more eyes on it. Motivation Recently the problem of "dependencies explosion" have been raised many times. A natural reaction is to push for limiting or even reversing split of projects into smaller crates (e.g. tokio). While small-crate approach indeed has its issues (e.g. in some cases it can increase maintenance cost a bit or make reviews harder, makes life of Linux package mainta…

[Pre-RFC] [idea] Cratespaces (crates as namespace, take 2... or 3?)

This is a slightly different take on the crates and namespaces suggestions made previously. Previous RFC's and discussions are linked at the end. Pre-RFC: Crate-spaces (crates as namespaces) Motivation: There's been a discussion around mono-crates versus many small crates for project like tokio. A group of small crates provides a number of benifits - granular compilation, independent versioning allowing for more flexible iteration, and an easy way to control how much code is compiled, compare…