PROVEN: from 14:57:01 to 18:43:23 today HEAD built main to 307aa45d… against the
expected 143dbb89…, with NO draft substituted (measured under gate.main.lock, no
gate_main alive). Auto-commit commit:2693 had adopted a mid-flight gate_main
substitution — its carve-out reverted main's TUs, gate_main re-wrote them, and
`git add -A src/` swept the unverified bodies in (a TOCTOU race, 14 s after a
bisect chunk banked). Every main batch after it was doomed before its first
draft was judged: m00–m03 card cycles drafted ~737, slated 160, banked 0, and
burned ~50 clean rebuilds bisecting innocent slates. commit:2712 restored the
green content by accident (it swept this investigation's diagnostic checkout).
gate_main: on any batch failure, ONE try_batch([]) control runs first — if HEAD
itself is red it prints BASELINE RED, leaves the slate reusable, exits 3 (R40).
clean_build no longer reports a linked-but-mismatched build as "no binary" (the
build target embeds the SHA check), the compile-conflict shortcut fires only on
error-shaped lines naming a symbol some draft in the slate actually uses (the
baseline's own func_800143AC implicit-decl WARNING was matching — every m04
chunk died with "drafts declaring it: []"), reverts narrow to top-level src/*.c
(main_tus) so a main gate can never destroy overlay lanes' in-flight work, and
--assert-baseline is a first-class mode.
main_lane: every cycle opens with gate_main --assert-baseline and REFUSES to
draft or gate against a red baseline (R43) — BaselineRed parks nothing, burns
no tries, writes .run/main_lane.BASELINE_RED, re-checks every 30 min.
Adopters (ox_campaign ×3, maintenance.sh, gate_stage, gate_lane, idiom_serial):
main's TUs (top-level src/*.c) are never staged and never reverted by an
overlay/maintenance lane — one writer (gate_main), one committer (main_lane,
after the whole-EXE SHA re-checks green). Unstage-after-add is race-free where
the old revert-then-add was the losing half of the TOCTOU.
Diagnosis, evidence and the full timeline: docs/tool-designs/main-lane-fix-s59.md
build_wave_atlas.py:
- taken-set was a hardcoded 'abcdefghijkl' wave-letter literal -> glob('.run/wave_*_cards.json')
(R33 derive, don't re-derive). NC: 634 -> 726 taken, strict superset, +92 cards from waves m/n
that the literal would have silently re-issued.
- --exclude-bins defaulted to 'main' on the REFUTED link-defect rationale; default now empty and
the help states the real reason (main cannot be gated incrementally; use tools/gate_main.py).
- new --only-bins allow-list: main waves need it, since gate_main rebuilds once per SLATE.
gate_lane.py: an unhandled gate_stage exception produced no JSON line -> v={} -> '0 banked',
indistinguishable from an honest empty gate (cost 2 cycles in P31). Now a non-zero rc or a missing
JSON line is labelled CRASH with the stderr tail, recorded in the results JSON, listed in the
summary as NEVER GATED, and exits non-zero. R39 NC both directions.
- the old glob('src/<binary>/*.c') found nothing for main (sources live at src/*.c), so every
main draft grouped under src=None: an R36 consumer-blindness, latent because main has never
been wave-gated (main is 0.5% matched, the largest coherent mass left)
- derive from corpus.stubs()[..].path instead; NC'd 3 ways: still-open wave-C drafts 3/3 agree,
overlay sample 96/96 agree (no regression), main now resolves None -> src/800.c
- tools/build_wave_atlas.py: wave selection off the frontier atlas, optimized for GATE
THROUGHPUT (gate cost scales with (binary,TU) groups, not drafts: wave C was 1.3 drafts per
rebuild; atlas selection concentrates to ~96) and weighted toward instruction mass
- checkpoint block refreshed for a fresh session (R30/checkpoint-before-pause): the TU-spread
test is the named FIRST action, the regen chain and gate contract are spelled out, and the
>=16 head's three open items are listed with their evidence.
- promote gate_lane.py into tools/ (it was scratchpad-only): accepts slate OR confirmed shapes,
explicit draft paths, R32 coverage assertion (refuses to report 0 as a result), dirty-tree
abort, no outer timeout, per-function propagation after.
- session: 179 commits, 177 instances banked, 5 R22 clean-fleet gates all 213/213.
Drew T