eval_proc was started before -d/GUI defines reached gd, so
``-d python_bin=...`` and the GUI ``python_bin`` preference were
silently ignored by the very subprocess that runs ``<| ... |>`` evals
(and only took effect for later items once the discovery cache had
already been seeded with the system interpreter). apply_overrides() is
now applied before eval_process_init(), and bins._resolve()'s cache is
keyed by (name, override) so a later param.yaml change re-resolves on
the next lookup.
The validation suite now ships a wrapper (run.sh / run.bat) that
creates a dedicated venv in the system temp dir and pins it via
``-d python_bin=...``. A new ``venv`` item asserts the override took
effect for both eval_proc and py_func paths, with a
``sys.prefix != sys.base_prefix`` marker to catch the case where the
override happens to be a system interpreter (path-equality alone would
miss it, the venv's ``bin/python3`` being a symlink to the host).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
