pathfinder: add cudart_static to the supported static libraries

cuda_pathfinder/cuda/pathfinder/_static_libs/find_static_lib.py

@@ -36,10 +36,10 @@ class _StaticLibInfo(TypedDict):
     site_packages_dirs: tuple[str, ...]
 
 
-def _cudadevrt_info() -> _StaticLibInfo:
+def _cuda_runtime_static_lib_info(stem: str) -> _StaticLibInfo:
     if not IS_WINDOWS:
         return {
-            "filename": "libcudadevrt.a",
+            "filename": f"lib{stem}.a",
             "ctk_rel_paths": ("lib64", "lib"),
             "conda_rel_paths": ("lib",),
             "site_packages_dirs": ("nvidia/cu13/lib", "nvidia/cuda_runtime/lib"),
@@ -49,15 +49,16 @@ def _cudadevrt_info() -> _StaticLibInfo:
     component_wheel_dirs = ("nvidia/cuda_runtime/lib/x64",) if arch_dir == "x64" else ()
     conda_fallback_dirs = ("lib",) if arch_dir == "x64" else ()
     return {
-        "filename": "cudadevrt.lib",
+        "filename": f"{stem}.lib",
         "ctk_rel_paths": (str(Path("lib", arch_dir)),),
         "conda_rel_paths": (str(Path("lib", arch_dir)), *conda_fallback_dirs),
         "site_packages_dirs": (f"nvidia/cu13/lib/{arch_dir}", *component_wheel_dirs),
     }
 
 
 _SUPPORTED_STATIC_LIBS_INFO: dict[str, _StaticLibInfo] = {
-    "cudadevrt": _cudadevrt_info(),
+    "cudadevrt": _cuda_runtime_static_lib_info("cudadevrt"),
+    "cudart_static": _cuda_runtime_static_lib_info("cudart_static"),
 }
 
 SUPPORTED_STATIC_LIBS: tuple[str, ...] = tuple(sorted(_SUPPORTED_STATIC_LIBS_INFO.keys()))

cuda_pathfinder/tests/test_find_static_lib.py

@@ -171,13 +171,51 @@ def test_cudadevrt_windows_paths_follow_python_arch(
     monkeypatch.setattr(find_static_lib_module, "IS_WINDOWS", True)
     monkeypatch.setattr(find_static_lib_module, "windows_python_arch", lambda: target_arch)
 
-    info = find_static_lib_module._cudadevrt_info()
+    info = find_static_lib_module._cuda_runtime_static_lib_info("cudadevrt")
 
+    assert info["filename"] == "cudadevrt.lib"
     assert info["ctk_rel_paths"] == expected_ctk_dirs
     assert info["conda_rel_paths"] == expected_conda_dirs
     assert info["site_packages_dirs"] == expected_site_packages_dirs
 
 
+@pytest.mark.parametrize(
+    ("is_windows", "expected_filename"),
+    ((False, "libcudart_static.a"), (True, "cudart_static.lib")),
+)
+@pytest.mark.agent_authored(model="claude-opus-5-5")
+def test_cudart_static_shares_cudadevrt_layout(monkeypatch, is_windows, expected_filename):
+    monkeypatch.setattr(find_static_lib_module, "IS_WINDOWS", is_windows)
+    monkeypatch.setattr(find_static_lib_module, "windows_python_arch", lambda: "x64")
+
+    cudart_static = find_static_lib_module._cuda_runtime_static_lib_info("cudart_static")
+    cudadevrt = find_static_lib_module._cuda_runtime_static_lib_info("cudadevrt")
+
+    assert cudart_static["filename"] == expected_filename
+    for key in ("ctk_rel_paths", "conda_rel_paths", "site_packages_dirs"):
+        assert cudart_static[key] == cudadevrt[key]
+
+
+@pytest.mark.usefixtures("clear_find_static_lib_cache")
+@pytest.mark.agent_authored(model="claude-opus-5-5")
+def test_locate_cudart_static_in_site_packages(monkeypatch, tmp_path):
+    info = find_static_lib_module._SUPPORTED_STATIC_LIBS_INFO["cudart_static"]
+    lib_dir = tmp_path / "site-packages" / Path(info["site_packages_dirs"][0])
+    expected_path = _make_static_lib_file(lib_dir, info["filename"])
+
+    monkeypatch.setattr(
+        find_static_lib_module,
+        "find_sub_dirs_all_sitepackages",
+        lambda _sub_dir: [str(lib_dir)],
+    )
+
+    located_lib = locate_static_lib("cudart_static")
+    assert located_lib.name == "cudart_static"
+    assert located_lib.abs_path == expected_path
+    assert located_lib.found_via == "site-packages"
+    assert find_static_lib("cudart_static") == expected_path
+
+
 @pytest.mark.usefixtures("clear_find_static_lib_cache")
 def test_find_static_lib_not_found_error_includes_cuda_home_directory_listing(monkeypatch, tmp_path):
     filename = CUDADEVRT_INFO["filename"]