The eager tiktoken tests were clearing all litellm modules from
sys.modules and re-importing, creating new module objects with different
class identities. This broke unittest.mock.patch for all subsequent
tests on the same xdist worker. Running these tests in subprocesses
provides perfect isolation.
Fixes: test_metadata_passed_to_custom_callback_codex_models,
test_oidc_github_success, test_oidc_google_cached,
test_oidc_google_failure,
test_encrypted_content_affinity_bypasses_rpm_limits, and 5 others.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The lazy loading implementation for encoding in __getattr__ was calling
tiktoken.get_encoding() directly without first setting TIKTOKEN_CACHE_DIR.
This caused tiktoken to attempt downloading the encoding file from the
internet instead of using the local copy bundled with litellm.
This fix uses _get_default_encoding() from _lazy_imports which properly
sets TIKTOKEN_CACHE_DIR before loading tiktoken, ensuring the local cache
is used.
