run_staged_search.py reported MISMATCH on its BASELINE arm -- the
LEAFSHARE=0/MULTIUSE=0 control every A/B compares against. Two facts
combined: driver.search_staged had no collapse_insearch parameter at all,
so every inner search() call inherited search()'s True default
unconditionally; and no example patterns.config sets the key, so the final
_native_score rescore got False from a bare load_config. Search optimised
one objective, the rescore graded another.
The 7ua fix pinned the key inside a fitness.load_config monkeypatch, but
that patch was installed only `if leaf_share or multi_use` -- so it fixed
every arm except the control.
Fixed in the right place: search_staged now HAS the parameter (default
True, byte-identical to the inherited default), threaded into all three
internal search() calls. The harness chooses the arm explicitly (COLLAPSE,
default 1), passes it to the search, and passes the SAME value to
_native_score, which overrides the key rather than hoping the config
carries it. The rescore mirrors the search by construction.
Verified on programme-house, budget 150:
baseline MISMATCH 1.56663e-08 vs 1.51708e-08 -> OK
COLLAPSE=0 (knob did not exist) -> OK 1.66216e-08
LEAFSHARE=1 / MULTIUSE=1 -> OK
COLLAPSE=0 scoring differently confirms the knob is not a no-op, and the
default arm's search result is unchanged, so no prior staged number moves.
Audited the other three search_staged callers: run_and_capture_91f.py
already pins collapse_insearch: True; run_island_ab.py never re-scores;
probe_harbor_floor.py did NOT pin it and had the same bug -- now fixed, and
that is the harness which produced every 13.x floor number.
The recorded mitigating factor -- only the continuous score moved, the fail
count matched, and the run_*_ab.sh greps read only the count -- is true and
is exactly what made it dangerous: a harness that reports MISMATCH on its
own control, invisibly to the metric of record, trains everyone to ignore
the warning.
Closes homemaker-py-4ok.
Lint at parity (46); tests 381 passed, 0 failed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MJ84Feep79Hhm3E4zZJmnB
500k serial full-stack harbor probe (probe_harbor_floor.py): 20 fails,
crinkliness 13→4, landlocked crinkliness ~13→2 of 20. Interior-O (default-ON,
erc.8) is 71d's named fix and dissolved its landlocked-crinkliness target;
residual now diffuse (top class edge-too-long). NO-GO on 71d.
Cumulative Phase-8 floor vs §12.2 baseline (leaf-share-relaxed): maple
136.0→80.3 (−41%), harbor 74.0→34.0 (−54%) — all from construction levers,
none from search machinery, per the epic thesis.
Closes erc epic: 71d/7u5/jrb/u8x superseded-by-construction; erc.5/erc.6
wont-fix (Diag A/B revisit conditions unmet). DESIGN §13.7.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JygRv4n2dcyDQqMiDRe7TN
