A long-lived worker kept the first `utils_slr` it ever imported in
`sys.modules`, so every later load unpickled against that stale class and
ignored the freshly downloaded `code/`. Courier Stratified retrain kept
failing on an old `StratifiedTransformerWrapper.fit` from a months-old
`/tmp/tmpvutfjrti` download.
`prepend_artifact_code_dir` now evicts cached modules shipped by the
artifact's `code/` that were imported from an artifact code directory,
and moves the directory to the front of `sys.path` when already present.
Modules installed in the image are never touched.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
vitor-aignosi
25f11fa943