uv-build Draws Gentoo Portability Backlash

uv-build is a sensible convenience for uv-native projects, but making it the default can shift small build-time benefits into real portability and maintenance costs for everyone downstream.

• –PEP 517 makes build backends interchangeable, so uv users can still build projects using flit-core, hatchling, or setuptools.
• –The backend currently targets pure-Python projects, where its performance advantage is unlikely to matter compared with dependency and compilation overhead.
• –Gentoo’s portability concern is especially relevant to source distributions, alternative architectures, and systems where Rust tooling is difficult to bootstrap.
• –Astral documents uv-build as optimized for portability and small binary size, making this dispute a useful test of whether those claims hold across distribution ecosystems. [Official documentation](https://docs.astral.sh/uv/configuration/build-backend/)
• –Maintainers should choose uv-build for concrete project needs rather than treating alignment with uv as sufficient justification.