uv is a new resolver and installer written in Rust. It claims to be substantially faster than Pip at resolving (and installing, although that is less relevant to us). It also claims to expose a CLI interface compatible with pip, so it supposedly can be used as a drop-in replacement. It notably does not claim to generate the same resolves as Pip (it uses PubGrub as the underlying solver).

See https://astral.sh/blog/uv for more.

uv makes some weighty claims, but we know from experience that the Python packaging ecosystem is messy, with many edge cases, ad-hoc behaviors, sharp edges, and de-facto standards that are not codified anywhere. It's as yet unclear how truly functional, or pip-compatible, uv is in real-world cases. So uv still requires substantial vetting by the community.

This ticket is to track and discuss the idea of embedding uv in Pex as an optional alternate resolver. We can evaluate potential benefits and drawbacks as uv gets more real-world usage, and if we see practical performance gains, before committing any effort to this.