fixup! feat(core.utils): run subprocess from neutral cwd to avoid source-tree shadow

Author: cpcloud

cuda_core/tests/test_program_cache.py

@@ -112,12 +112,11 @@ def close(self):
     assert closed == [True]
 
 
-def test_cuda_core_utils_memoryview_import_is_lightweight():
+def test_cuda_core_utils_memoryview_import_is_lightweight(tmp_path):
     """``from cuda.core.utils import StridedMemoryView`` must NOT transitively
     import the program-cache backends; the cache modules pull in extra
     driver/NVRTC machinery that memoryview-only consumers have no reason
     to load."""
-    import os
     import subprocess
     import sys
     import textwrap
@@ -135,12 +134,11 @@ def test_cuda_core_utils_memoryview_import_is_lightweight():
         _ = u.make_program_cache_key
         assert "cuda.core.utils._program_cache" in sys.modules
     """)
-    # Forward pytest's sys.path to the subprocess via PYTHONPATH so it can
-    # find the same cuda.core install the parent process is using (CI runs
-    # may rely on pytest-added rootdirs that env-only inheritance misses).
-    env = os.environ.copy()
-    env["PYTHONPATH"] = os.pathsep.join(filter(None, sys.path))
-    subprocess.run([sys.executable, "-c", prog], check=True, env=env)  # noqa: S603
+    # Run from a neutral cwd so Python's implicit ``sys.path[0]=''`` does not
+    # resolve to the unbuilt cuda_core source tree (which lacks the
+    # setuptools-scm-generated ``_version.py``). The subprocess must import
+    # the installed cuda.core from site-packages.
+    subprocess.run([sys.executable, "-c", prog], check=True, cwd=str(tmp_path))  # noqa: S603
 
 
 # ---------------------------------------------------------------------------