`test_the_four_existing_goldens_are_untouched` ran `git status` with
`check=True` in a `git archive` extract and raised `CalledProcessError`.
Measured 2026-09-19 it was the single failure of the whole suite run from
a clean extract -- twice reported as a round's one failure, twice by a
round that had not touched the file.
Both arms measure the CHECKOUT with `git`, so an extract has nothing to
ask. It skips with the reason stated, never silently: a checkout still
has to answer. Reproduced before and after on a non-repository copy --
`CalledProcessError` -> `SKIPPED [1] ... not a git checkout`.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
