Remove same-graph merging in resolver

crates/uv-resolver/src/resolution/graph.rs

@@ -1,7 +1,7 @@
 use indexmap::IndexSet;
 use petgraph::{
-    graph::{Graph, NodeIndex},
-    Directed, Direction,
+    Directed,
+    Direction, graph::{Graph, NodeIndex},
 };
 use pubgrub::Range;
 use rustc_hash::{FxBuildHasher, FxHashMap, FxHashSet};
@@ -18,17 +18,17 @@ use uv_distribution::Metadata;
 use uv_git::GitResolver;
 use uv_normalize::{ExtraName, GroupName, PackageName};
 
+use crate::{
+    InMemoryIndex, MetadataResponse, Options, PythonRequirement, RequiresPython, ResolveError,
+    ResolverMarkers, VersionsResponse,
+};
 use crate::pins::FilePins;
 use crate::preferences::Preferences;
 use crate::python_requirement::PythonTarget;
 use crate::redirect::url_to_precise;
 use crate::resolution::AnnotatedDist;
 use crate::resolution_mode::ResolutionStrategy;
 use crate::resolver::{Resolution, ResolutionDependencyEdge, ResolutionPackage};
-use crate::{
-    InMemoryIndex, MetadataResponse, Options, PythonRequirement, RequiresPython, ResolveError,
-    ResolverMarkers, VersionsResponse,
-};
 
 pub(crate) type MarkersForDistribution = FxHashMap<(Version, Option<VerbatimUrl>), Vec<MarkerTree>>;
 

crates/uv-resolver/src/resolver/mod.rs

@@ -400,29 +400,6 @@ impl<InstalledPackages: InstalledPackagesProvider> ResolverState<InstalledPackag
                         );
                     }
 
-                    // If another fork had the same resolution, merge into that fork instead.
-                    if let Some(existing_resolution) = resolutions
-                        .iter_mut()
-                        .find(|existing_resolution| resolution.same_graph(existing_resolution))
-                    {
-                        let ResolverMarkers::Fork(existing_markers) = &existing_resolution.markers
-                        else {
-                            panic!("A non-forking resolution exists in forking mode")
-                        };
-                        let mut new_markers = existing_markers.clone();
-                        new_markers.or(resolution
-                            .markers
-                            .fork_markers()
-                            .expect("A non-forking resolution exists in forking mode")
-                            .clone());
-                        existing_resolution.markers = if new_markers.is_true() {
-                            ResolverMarkers::universal(vec![])
-                        } else {
-                            ResolverMarkers::Fork(new_markers)
-                        };
-                        continue 'FORK;
-                    }
-
                     Self::trace_resolution(&resolution);
                     resolutions.push(resolution);
                     continue 'FORK;
@@ -2516,21 +2493,6 @@ pub(crate) struct ResolutionDependencyEdge {
     pub(crate) marker: MarkerTree,
 }
 
-impl Resolution {
-    /// Whether we got two identical resolutions in two separate forks.
-    ///
-    /// Ignores pins since the which distribution we prioritized for each version doesn't matter.
-    fn same_graph(&self, other: &Self) -> bool {
-        // TODO(konsti): The edges being equal is not a requirement for the graph being equal. While
-        // an exact solution is too much here, we should ignore different in edges that point to
-        // nodes that are always installed. Example: root requires foo, root requires bar. bar
-        // forks, and one for the branches has bar -> foo while the other doesn't. The resolution
-        // is still the same graph since the presence or absence of the bar -> foo edge cannot
-        // change which packages and versions are installed.
-        self.nodes == other.nodes && self.edges == other.edges
-    }
-}
-
 impl ResolutionPackage {
     pub(crate) fn is_base(&self) -> bool {
         self.extra.is_none() && self.dev.is_none()

crates/uv/tests/ecosystem.rs

@@ -33,9 +33,7 @@ fn packse() -> Result<()> {
 // Source: https://github.com/konstin/github-wikidata-bot/blob/8218d20985eb480cb8633026f9dabc9e5ec4b5e3/pyproject.toml
 #[test]
 fn github_wikidata_bot() -> Result<()> {
-    // TODO(charlie): This test became non-deterministic in https://github.com/astral-sh/uv/pull/6065.
-    // However, that fix is _correct_, and the non-determinism itself is an existing bug.
-    lock_ecosystem_package_non_deterministic("3.12", "github-wikidata-bot")
+    lock_ecosystem_package("3.12", "github-wikidata-bot")
 }
 
 // Source: https://github.com/psf/black/blob/9ff047a9575f105f659043f28573e1941e9cdfb3/pyproject.toml

crates/uv/tests/lock.rs

@@ -3626,19 +3626,17 @@ fn lock_python_version_marker_complement() -> Result<()> {
         );
     });
 
-    // TODO(charlie): This test became non-deterministic in https://github.com/astral-sh/uv/pull/6065.
-    // But that fix is correct, and the non-determinism itself is a bug.
-    // // Re-run with `--locked`.
-    // uv_snapshot!(context.filters(), context.lock().arg("--locked"), @r###"
-    // success: false
-    // exit_code: 2
-    // ----- stdout -----
-    //
-    // ----- stderr -----
-    // warning: `uv lock` is experimental and may change without warning
-    // Resolved 4 packages in [TIME]
-    // error: The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.
-    // "###);
+    // Re-run with `--locked`.
+    uv_snapshot!(context.filters(), context.lock().arg("--locked"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv lock` is experimental and may change without warning
+    Resolved 4 packages in [TIME]
+    error: The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.
+    "###);
 
     Ok(())
 }