expand local_cycle_hint() logic to catch more cases

crates/uv-resolver/src/pubgrub/report.rs

@@ -737,26 +737,59 @@ impl PubGrubReportFormatter<'_> {
         for local_package in workspace_members {
             let pkg = PubGrubPackage::from_package(local_package.clone(), None, None.into());
             if derived.terms.contains_key(&pkg) {
-                let DerivationTree::External(External::FromDependencyOf(src1, _, dst1, _)) =
+                // Check for a direct loop between two dependencies, involving a local package...
+                if let DerivationTree::External(External::FromDependencyOf(src1, _, dst1, _)) =
                     derived.cause1.borrow()
-                else {
-                    continue;
-                };
-
-                let DerivationTree::External(External::FromDependencyOf(src2, _, dst2, _)) =
+                {
+                    let DerivationTree::External(External::FromDependencyOf(src2, _, dst2, _)) =
+                        derived.cause2.borrow()
+                    else {
+                        continue;
+                    };
+
+                    // Detect a direct loop condition, with two opposing edges between the same
+                    // packages.
+                    let cycle_edge_first =
+                        src1.name_no_root().is_some() && src1.name_no_root() == dst2.name_no_root();
+                    let cycle_edge_second =
+                        dst1.name_no_root().is_some() && dst1.name_no_root() == src2.name_no_root();
+                    if cycle_edge_first && cycle_edge_second {
+                        output_hints.insert(PubGrubHint::WorkspacePackageNoVersions {
+                            package: pkg.clone(),
+                        });
+                    }
+                }
+                // ... otherwise, check left child for an error caused by a failed dependency
+                // on a local package...
+                else if let DerivationTree::External(External::NoVersions(_, _)) =
+                    derived.cause1.borrow()
+                {
+                    let DerivationTree::External(External::FromDependencyOf(_, _, dst, _)) =
+                        derived.cause2.borrow()
+                    else {
+                        continue;
+                    };
+                    if *dst == pkg {
+                        output_hints.insert(PubGrubHint::WorkspacePackageNoVersions {
+                            package: pkg.clone(),
+                        });
+                    }
+                }
+                // ... otherwise, check right child for an error caused by a failed dependency
+                // on a local package...
+                else if let DerivationTree::External(External::NoVersions(_, _)) =
                     derived.cause2.borrow()
-                else {
-                    continue;
-                };
-
-                let cycle_edge_first =
-                    src1.name_no_root().is_some() && src1.name_no_root() == dst2.name_no_root();
-                let cycle_edge_second =
-                    dst1.name_no_root().is_some() && dst1.name_no_root() == src2.name_no_root();
-                if cycle_edge_first && cycle_edge_second {
-                    output_hints.insert(PubGrubHint::WorkspacePackageNoVersions {
-                        package: pkg.clone(),
-                    });
+                {
+                    let DerivationTree::External(External::FromDependencyOf(_, _, dst, _)) =
+                        derived.cause1.borrow()
+                    else {
+                        continue;
+                    };
+                    if *dst == pkg {
+                        output_hints.insert(PubGrubHint::WorkspacePackageNoVersions {
+                            package: pkg.clone(),
+                        });
+                    }
                 }
             }
         }

crates/uv/tests/edit.rs

@@ -4824,6 +4824,7 @@ fn add_error_local_cycle() -> Result<()> {
         dependencies = []
     "#})?;
 
+    // Pinned constrained, check for a direct dependency loop.
     uv_snapshot!(context.filters(), context.add().arg("dagster-webserver==1.6.13"), @r###"
     success: false
     exit_code: 1
@@ -4837,5 +4838,30 @@ fn add_error_local_cycle() -> Result<()> {
       help: If this is intentional, run `uv add --frozen` to skip the lock and sync steps.
     "###);
 
+    // Constraint with several available versions, check for an indirect dependency loop.
+    uv_snapshot!(context.filters(), context.add().arg("dagster-webserver>=1.6.11,<1.7.0"), @r###"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+
+    ----- stderr -----
+      × No solution found when resolving dependencies:
+      ╰─▶ Because only the following versions of dagster-webserver are available:
+              dagster-webserver<=1.6.13
+              dagster-webserver>1.7.0
+          and dagster-webserver==1.6.11 depends on your project, we can conclude that all of:
+              dagster-webserver>=1.6.11,<1.6.12
+              dagster-webserver>1.6.13,<1.7.0
+          depend on your project.
+          And because dagster-webserver==1.6.12 depends on your project, we can conclude that all of:
+              dagster-webserver>=1.6.11,<1.6.13
+              dagster-webserver>1.6.13,<1.7.0
+          depend on your project.
+          And because dagster-webserver==1.6.13 depends on your project and your project depends on dagster-webserver>=1.6.11,<1.7.0, we can conclude that your project's requirements are unsatisfiable.
+
+          hint: Resolution failed on a dependency ('dagster') which has the same name as your local package ('dagster'). Consider checking your project for possible name conflicts with packages in the index.
+      help: If this is intentional, run `uv add --frozen` to skip the lock and sync steps.
+    "###);
+
     Ok(())
 }