The old comparison only commented when the PASS/FAIL/ERROR/SKIP *counts*
changed vs main, so it was blind to net-zero changes (one test fixed, one
broken). diff-gnu.sh also compared against an unextracted (empty) baseline,
flagging every current failure as a regression, and the published baseline
could be stale.
Adopt the sed/grep design:
- build-gnu.sh / build-bfs.sh now emit a per-test JSON summary
(findutils-gnu-full-result.json / bfs-full-result.json) listing every
test's name + PASS/FAIL/SKIP, via the new gnu_json_result.py /
bfs_json_result.py.
- compare_test_results.py diffs the set of failing test names against a
reference, writing a human-readable result file (empty when nothing
changed) and exiting non-zero only on new, non-intermittent failures.
- compat.yml fetches the reference *-full-result.json from the default
branch's latest run (dawidd6/action-download-artifact) and uploads a
comparison artifact per suite.
- comment.yml posts a PR comment whenever the comparison is non-empty,
i.e. on any per-test improvement or regression regardless of net count.
- ignore-intermittent.txt lists known-flaky tests, reported but not
failing the job.
Remove the superseded compare_gnu_result.py / compare_bfs_result.py /
diff-gnu.sh / diff-bfs.sh.
