What would it take for `sysroot` crates to be treated as "just" another dependency in rust-analyzer?

Hi! A colleague is making some changes of how the sysroot is configured and exposed in Buck2's rust_rules. They asked me a question I didn't have the answer to: if we were building std from source, could it be treated/exposed as just another dependency in a rust-project.json? I know that there's some special handling for sysroot crates inside of project-model/src/sysroot.rs and Lukas mentioned that dependencies of std require weird workarounds to avoid circular dependencies.

Is treating sysroot crates as "just" another dependency de-facto blocked on the stabilization of build-std?

(This isn't a feature request; it's more of a "how hard would it be to support this" and if y'all don't have an answer off-hand, I'll treat it as "build-std needs to be stabilized first".)

Start with crates/project-model/src/sysroot.rs and the rust-project.json sysroot handling described in the issue. Review the linked build-std documentation and the referenced pull-request discussion, then document whether sysroot crates can be modeled as ordinary dependencies and which blockers remain.