test(pathfinder): handle cuTENSORMg removal in cuTENSOR 2.8 (#2809)

Author: rwgk

cuda_pathfinder/tests/local_helpers.py

@@ -1,16 +1,20 @@
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 import functools
 import importlib.metadata
 import re
 
+from packaging.version import Version
+
 
 @functools.cache
-def have_distribution(name_pattern: str) -> bool:
+def have_distribution(name_pattern: str, *, minimum_version: str | None = None) -> bool:
     re_name_pattern = re.compile(name_pattern)
+    parsed_minimum_version = Version(minimum_version) if minimum_version is not None else None
     return any(
         re_name_pattern.match(dist.metadata["Name"])
+        and (parsed_minimum_version is None or Version(dist.version) >= parsed_minimum_version)
         for dist in importlib.metadata.distributions()
         if "Name" in dist.metadata
     )

cuda_pathfinder/tests/test_load_nvidia_dynamic_lib.py

@@ -4,6 +4,7 @@
 import os
 import platform
 from pathlib import Path
+from types import SimpleNamespace
 
 import pytest
 from child_load_nvidia_dynamic_lib_helper import (
@@ -123,12 +124,39 @@ def test_known_but_platform_unavailable_libname_raises_dynamic_lib_not_available
 def _is_expected_load_nvidia_dynamic_lib_failure(libname):
     if libname == "nvpl_fftw" and platform.machine().lower() != "aarch64":
         return True
+    if libname == "cutensorMg":
+        # cuTENSOR 2.8 removed cuTENSORMg in favor of cuTENSORMp.
+        return have_distribution(r"^cutensor-cu(?:12|13)$", minimum_version="2.8")
     dist_name_pattern = IMPORTLIB_METADATA_DISTRIBUTIONS_NAMES.get(libname)
     if dist_name_pattern is not None:
         return not have_distribution(dist_name_pattern)
     return False
 
 
+@pytest.mark.parametrize(
+    ("installed_distributions", "expected"),
+    [
+        ([], False),
+        ([SimpleNamespace(metadata={"Name": "cutensor-cu13"}, version="2.7.0")], False),
+        ([SimpleNamespace(metadata={"Name": "cutensor-cu12"}, version="2.8.0")], True),
+        ([SimpleNamespace(metadata={"Name": "cutensor-cu13"}, version="2.9.0")], True),
+        ([SimpleNamespace(metadata={"Name": "unrelated-package"}, version="2.8.0")], False),
+    ],
+)
+@pytest.mark.agent_authored(model="gpt-5.6-sol")
+def test_cutensor_mg_expected_failure_follows_installed_cutensor_version(
+    mocker,
+    installed_distributions,
+    expected,
+):
+    mocker.patch("local_helpers.importlib.metadata.distributions", return_value=installed_distributions)
+    have_distribution.cache_clear()
+    try:
+        assert _is_expected_load_nvidia_dynamic_lib_failure("cutensorMg") is expected
+    finally:
+        have_distribution.cache_clear()
+
+
 @pytest.mark.parametrize(
     "libname",
     supported_nvidia_libs.SUPPORTED_WINDOWS_DLLS if IS_WINDOWS else supported_nvidia_libs.SUPPORTED_LINUX_SONAMES,