fix transitive_marker handling

src/poetry/mixology/term.py

@@ -95,7 +95,13 @@ def _relation(self, other: Term) -> str:
                     return SetRelation.SUBSET
 
                 # foo ^1.5.0 is disjoint with not foo ^1.0.0
-                if other_constraint.allows_all(self.constraint):
+                if (
+                    other_constraint.allows_all(self.constraint)
+                    # if transitive markers are not equal we have to handle it
+                    # as overlapping so that markers are merged later
+                    and self.dependency.transitive_marker
+                    == other.dependency.transitive_marker
+                ):
                     return SetRelation.DISJOINT
 
                 # foo ^1.0.0 overlaps not foo ^1.5.0
@@ -177,7 +183,12 @@ def _non_empty_term(
             and other.dependency.is_direct_origin()
             else self.dependency
         )
-        return Term(dependency.with_constraint(constraint), is_positive)
+        new_dep = dependency.with_constraint(constraint)
+        if is_positive and other.is_positive():
+            new_dep.transitive_marker = self.dependency.transitive_marker.union(
+                other.dependency.transitive_marker
+            )
+        return Term(new_dep, is_positive)
 
     def __str__(self) -> str:
         prefix = "not " if not self.is_positive() else ""

src/poetry/mixology/version_solver.py

@@ -426,17 +426,19 @@ def _resolve_conflict(self, incompatibility: Incompatibility) -> Incompatibility
 
         raise SolveFailureError(incompatibility)
 
-    def _choose_package_version(self) -> str | None:
+    def _choose_next(self, unsatisfied: list[Dependency]) -> Dependency:
         """
-        Tries to select a version of a required package.
-
-        Returns the name of the package whose incompatibilities should be
-        propagated by _propagate(), or None indicating that version solving is
-        complete and a solution has been found.
+        The original algorithm proposes to prefer packages with as few remaining
+        versions as possible, so that if a conflict is necessary it's forced quickly.
+        https://github.com/dart-lang/pub/blob/master/doc/solver.md#decision-making
+        However, this leads to the famous boto3 vs. urllib3 issue, so we prefer
+        packages with more remaining versions (see
+        https://github.com/python-poetry/poetry/pull/8255#issuecomment-1657198242
+        for more details).
+        In order to provide results that are as deterministic as possible
+        and consistent between `poetry lock` and `poetry update`, the return value
+        of two different dependencies should not be equal if possible.
         """
-        unsatisfied = self._solution.unsatisfied
-        if not unsatisfied:
-            return None
 
         class Preference:
             """
@@ -451,16 +453,6 @@ class Preference:
             LOCKED = 3
             DEFAULT = 4
 
-        # The original algorithm proposes to prefer packages with as few remaining
-        # versions as possible, so that if a conflict is necessary it's forced quickly.
-        # https://github.com/dart-lang/pub/blob/master/doc/solver.md#decision-making
-        # However, this leads to the famous boto3 vs. urllib3 issue, so we prefer
-        # packages with more remaining versions (see
-        # https://github.com/python-poetry/poetry/pull/8255#issuecomment-1657198242
-        # for more details).
-        # In order to provide results that are as deterministic as possible
-        # and consistent between `poetry lock` and `poetry update`, the return value
-        # of two different dependencies should not be equal if possible.
         def _get_min(dependency: Dependency) -> tuple[bool, int, int]:
             # Direct origin dependencies must be handled first: we don't want to resolve
             # a regular dependency for some package only to find later that we had a
@@ -490,7 +482,21 @@ def _get_min(dependency: Dependency) -> tuple[bool, int, int]:
                 preference = Preference.DEFAULT
             return is_specific_marker, preference, -num_packages
 
-        dependency = min(unsatisfied, key=_get_min)
+        return min(unsatisfied, key=_get_min)
+
+    def _choose_package_version(self) -> str | None:
+        """
+        Tries to select a version of a required package.
+
+        Returns the name of the package whose incompatibilities should be
+        propagated by _propagate(), or None indicating that version solving is
+        complete and a solution has been found.
+        """
+        unsatisfied = self._solution.unsatisfied
+        if not unsatisfied:
+            return None
+
+        dependency = self._choose_next(unsatisfied)
 
         locked = self._provider.get_locked(dependency)
         if locked is None:
@@ -508,6 +514,8 @@ def _get_min(dependency: Dependency) -> tuple[bool, int, int]:
 
                 complete_name = dependency.complete_name
                 return complete_name
+
+            package.dependency.transitive_marker = dependency.transitive_marker
         else:
             package = locked
 

tests/puzzle/test_solver.py

@@ -4329,8 +4329,13 @@ def test_solver_can_resolve_python_restricted_package_dependencies(
     )
 
 
+@pytest.mark.parametrize("virtualenv_before_pre_commit", [False, True])
 def test_solver_should_not_raise_errors_for_irrelevant_transitive_python_constraints(
-    solver: Solver, repo: Repository, package: ProjectPackage
+    solver: Solver,
+    repo: Repository,
+    package: ProjectPackage,
+    mocker: MockerFixture,
+    virtualenv_before_pre_commit: bool,
 ) -> None:
     package.python_versions = "~2.7 || ^3.5"
     set_package_python_versions(solver.provider, "~2.7 || ^3.5")
@@ -4367,6 +4372,24 @@ def test_solver_should_not_raise_errors_for_irrelevant_transitive_python_constra
     repo.add_package(pre_commit)
     repo.add_package(importlib_resources)
     repo.add_package(importlib_resources_3_2_1)
+
+    def patched_choose_next(unsatisfied: list[Dependency]) -> Dependency:
+        order = (
+            ("root", "virtualenv", "pre-commit", "importlib-resources")
+            if virtualenv_before_pre_commit
+            else ("root", "pre-commit", "virtualenv", "importlib-resources")
+        )
+        for preferred in order:
+            for dep in unsatisfied:
+                if dep.name == preferred:
+                    return dep
+        raise RuntimeError
+
+    mocker.patch(
+        "poetry.mixology.version_solver.VersionSolver._choose_next",
+        side_effect=patched_choose_next,
+    )
+
     transaction = solver.solve()
 
     check_solver_result(