[BUG]: test_program_cache_tmp_dir_created_owner_only fails under a setgid parent directory #3214

Is this a duplicate?

• I confirmed there appear to be no duplicate issues for this bug and that I agree to the Code of Conduct

Type of Bug

Something else (test-only failure)

Component

cuda.core

Describe the bug

With TMPDIR in a group-shared directory that has the setgid bit (mode 2770), cuda_core/tests/test_program_cache.py::test_program_cache_tmp_dir_created_owner_only fails:

AssertionError: tmp has mode 0o2700

FileStreamProgramCache creates tmp with mkdir(mode=0o700), and on Linux a new directory inherits S_ISGID from a setgid parent. The test compares stat.S_IMODE(...), which keeps the setgid bit, against 0o700. The directory is still owner-only: setgid on a directory only sets the group of new entries and grants no access. Under a parent without setgid, the same test passes.

How to Reproduce

mkdir -p /tmp/sg && chmod 2770 /tmp/sg
TMPDIR=/tmp/sg pytest cuda_core/tests/test_program_cache.py -k tmp_dir_created_owner_only

(The group-shared parent must be one where you may set the setgid bit; any directory with mode 2770 reproduces it.)

Expected behavior

The test checks that tmp is owner-only, which it is; the inherited setgid bit does not grant access and should not fail it.

Proposed fix

Compare only the access bits, stat.S_IMODE(os.stat(root / "tmp").st_mode) & 0o777. With that change, the test passes under the setgid TMPDIR above. I can open a PR.

The fix was written with Claude Opus 5.5 and reviewed by the contributor.

Environment

GPU: B300 (cc 10.3, x86_64) | driver 610.57.04 | CUDA 13.4.2 (local CTK) | Python 3.12 | cuda-python 2da9c65a