Charlie Marsh 7eaed07f6c Move conflicting dependencies into PubGrub (#1796) ... ## Summary This revives a PR from long ago (https://github.com/astral-sh/uv/pull/383 and https://github.com/zanieb/pubgrub/pull/24) that modifies how we deal with dependencies that are declared multiple times within a single package. To quote from the originating PR: > Uses an experimental pubgrub branch (#370) that allows us to handle multiple version ranges for a single dependency to the solver which results in better error messages because the derivation tree contains all of the relevant versions. Previously, the version ranges were merged (by us) in the resolver before handing them to pubgrub since only one range could be provided per package. Since we don't merge the versions anymore, we no longer give the solver an empty range for conflicting requirements; instead the solver comes to that conclusion from the provided versions. You can see the improved error message for direct dependencies in [this snapshot](https://github.com/astral-sh/puffin/pull/383/files#diff-a0437f2c20cde5e2f15199a3bf81a102b92580063268417847ec9c793a115bd0). The main issue with that PR was around its handling of URL dependencies, so this PR _also_ refactors how we handle those. Previously, we stored URL dependencies on `PubGrubPackage`, but they were omitted from the hash and equality implementations of `PubGrubPackage`. This led to some really careful codepaths wherein we had to ensure that we always visited URLs before non-URL packages, so that the URL-inclusive versions were included in any hashmaps, etc. I considered preserving this approach, but it would require us to rely on lots of internal details of PubGrub (since we'd now be relying on PubGrub to merge those packages in the "right" order). So, instead, we now _always_ set the URL on a given package, whenever that package was _given_ a URL upfront. I think this is easier to reason about: if the user provided a URL for `flask`, then we should just always add the URL for `flask`. If we see some other URL for `flask`, we error, like before. If we see some unknown URL for `flask`, we error, like before. Closes https://github.com/astral-sh/uv/issues/1522. Closes https://github.com/astral-sh/uv/issues/1821. Closes https://github.com/astral-sh/uv/issues/1615.		2024-02-21 21:27:58 -05:00
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resolver.rs	Move conflicting dependencies into PubGrub (#1796)	2024-02-21 21:27:58 -05:00