Name of Failure:

test-auth-oidc-eks failing on test_4_1_reauthentication_succeeds and test_4_2_read_commands_fail_if_reauthentication_fails in test/test_auth_oidc.py::TestAuthOIDCMachine, build variant auth-oidc-ubuntu-22.

Link to task:

https://spruce.corp.mongodb.com/task/mongo_python_driver_auth_oidc_ubuntu_22_test_auth_oidc_eks_2d2daed7feb775e328fa1668f34047a1c239444c_26_08_12_14_20_45/logs?execution=0

Context of when and why the failure occurred:

Both tests inject a failCommand with errorCode: 391 on a find and expect OperationFailure to be raised, but it isn't — AssertionError: OperationFailure not raised.

This is a recurring flake rather than a new regression: task history on auth-oidc-ubuntu-22 shows failures interleaved with passes over the last ~3 weeks (e.g. revisions 2d2daed7fe, d03d621ef5, 674203727b failed; 4efdc82c7f, e504eb60b6, 70573fe568 passed; 74c011f9aa, 500e1d0c4c failed; 48238a1a84 passed; etc.). Task reliability for 2026-07-14 to 2026-08-13: 10 success / 13 failed of 23 total runs.

A related but distinct closed ticket, PYTHON-5476 ("test-auth-oidc-eks segmentation fault"), covers a different symptom (segfault) on the same task and is not a duplicate of this assertion failure.

Stack trace:

            with self.assertRaises(OperationFailure):
E           AssertionError: OperationFailure not raised
test/test_auth_oidc.py:1022: AssertionError
...
FAILED test/test_auth_oidc.py::TestAuthOIDCMachine::test_4_1_reauthentication_succeeds
FAILED test/test_auth_oidc.py::TestAuthOIDCMachine::test_4_2_read_commands_fail_if_reauthentication_fails
==== 2 failed, 36 passed, 69 skipped, 8930 deselected in 100.51s (0:01:40) =====
error: recipe `run-tests` failed on line 88 with exit code 1