Comment by charliermarsh

> Man, it's easy to be fast when you're wrong. But of course it is fast because Rust not because it just skips the hard parts of dependency constraint solving and hopes people don't notice.

We ignore upper bounds because it leads to a better solve. You can read my comment here: https://discuss.python.org/t/requires-python-upper-limits/12....

> Ambiguity detection is important.

I think you're misunderstanding why we do this: it's a security feature. pip's design is inherently vulnerable to dependency confusion attacks, since packages of the same name across indexes are considered equally trusted by pip. You can look up the torchtriton attack to learn more.

> Stuff like this sense unlikely to contribute to overall runtime, but it does decrease flexibility.

I think you're misinformed. We support all of these features: system- and per-user configuration files, environment variables, etc. We just don't read _pip's_ configuration file, which is intended for pip, not uv.