Summary

TestExplicitQueryableEncryption.test_02_insert_encrypted_indexed_and_find_contention fails consistently on Python 3.14 and 3.14t (free-threaded) across all encryption build variants and platforms.

Observed Behavior

Both the sync (test.test_encryption) and async (test.asynchronous.test_encryption) versions of test_02_insert_encrypted_indexed_and_find_contention fail on every encryption build variant while all other ~1109 tests pass.

Affected Configurations

• Python versions: 3.14, 3.14t (free-threaded only — other versions are unaffected)
• Build variants: encryption-rhel8, encryption-crypt_shared-rhel8, encryption-pyopenssl-rhel8, encryption-macos, encryption-crypt_shared-macos, encryption-win64, encryption-crypt_shared-win64
• Topologies: replica set, sharded cluster

Reproduction

Observed in Evergreen patch 6a303402094e5b000729e4d4 — 14 tasks failed, all with exactly 2 test failures (sync + async) of this same test.

Notes

The failure is isolated to this single test across all platforms, suggesting a Python 3.14 compatibility issue in the Queryable Encryption contention test logic rather than a broad infrastructure problem.