From a292817d573eaa4a623ce730b27f8ce02de95c7a Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Mon, 11 Mar 2024 10:51:42 -0700
Subject: [PATCH] Ignore inverse dependencies when building graph (#2360)

## Summary

It turns out that when we iterate over the incompatibilities of a
package, PubGrub will _also_ show us the inverse dependencies. I suspect
this was rare, because we have a version check at the bottom... So, this
specifically required that you had some dependency that didn't end up
appearing in the output resolution, but that matched the version
constraints of the package you care about.

In this case, `langchain-community` depends on `langchain-core`. So we
were seeing an incompatibility like:

```rust
FromDependencyOf(Package(PackageName("langchain-community"), None, None), Range { segments: [(Included("0.0.10"), Included("0.0.10")), (Included("0.0.11"), Included("0.0.11"))] }, Package(PackageName("langchain-core"), None, None), Range { segments: [(Included("0.1.8"), Excluded("0.2"))] })
```

Where we were iterating over `langchain-core`, and looking for version
`0.0.11`... which happens to match `langchain-community`.
(`langchain-community was omitted from the resolution; hence, it didn't
exist in the map.)

Closes https://github.com/astral-sh/uv/issues/2358.
---
 crates/uv-resolver/src/resolution.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/crates/uv-resolver/src/resolution.rs b/crates/uv-resolver/src/resolution.rs
index 31265f8c4..acd02060e 100644
--- a/crates/uv-resolver/src/resolution.rs
+++ b/crates/uv-resolver/src/resolution.rs
@@ -213,6 +213,14 @@ impl ResolutionGraph {
                     dependency_range,
                 ) = &state.incompatibility_store[*id].kind
                 {
+                    // `Kind::FromDependencyOf` will include inverse dependencies. That is, if we're
+                    // looking for a package `A`, this list will include incompatibilities of
+                    // package `B` _depending on_ `A`. We're only interested in packages that `A`
+                    // depends on.
+                    if package != self_package {
+                        continue;
+                    }
+
                     let PubGrubPackage::Package(self_package, _, _) = self_package else {
                         continue;
                     };