fix(corpus-ratchet): remove the t27c test step; it was measured on the wrong tree

[gHashTag]

Refs #2292
Refs #2288
Refs #2289

Removes the cargo test -p t27c --release step added 34 minutes earlier in ce6ea628b (PR #2291). I landed that step, it went red on its first run on master, and this takes it back out.

Why it was wrong

ce6ea628b was justified by "1221 passed, 0 failed, 0 ignored". That measurement was real. It was taken in the wrong working tree — the host checkout sits on feat/wave-547/host-heapsort, while the gate runs on master, and the two are nowhere near each other:

	feat/wave-547/host-heapsort	origin/master
bootstrap/src/compiler.rs	22,142 lines	36,970 lines
#[test] in bootstrap/src	1,781	1,622
cargo test -p t27c main bin	895 passed, 0 failed	1602 passed, 13 failed, 2 ignored

Run that went red: https://github.com/gHashTag/t27/actions/runs/32330080992

A gate that lands red gets disabled rather than obeyed, so it comes out rather than being silenced, baselined in place, or "fixed" by editing tests. The 13 failing test names are recorded in #2292 along with the plan to re-land this as a ratchet.

The failure routing did work

Worth keeping on the record, because it is the one part that behaved as designed:

failure   Unit tests (cargo test -p t27c)
success   Explain a unit-test failure      <- correct explainer fired
skipped   Run the corpus ratchet
skipped   Explain a failure                <- ratchet explainer correctly did NOT fire

So the steps.ratchet.outcome scoping is kept. As a bare failure() it answers a failing Build t27c with "add an entry to docs/reports/suite_expectations.json", which is wrong independently of any test step. That is the only change from ce6ea628b that survives.

Diff against the pre-gate state

Against eeb779e4c (master before #2291), corpus-ratchet.yml differs only by the scoping fix and a comment block recording why the step must not be re-added without a measurement taken on master. The red step and its explainer are gone.

Honesty limits

• 13 is a lower bound, not the failing count. cargo test stops at the first failing target, so the 21 test binaries in bootstrap/tests/ never ran on master. Their state is unmeasured. A ratchet baseline needs --no-fail-fast first.
• This made things worse for 34 minutes, not merely no better. corpus-ratchet was already failing at Run the corpus ratchet on eeb779e4c, 57a53005a, 2255e4c32, bffd38982 and 400850702. A failing step in front of it short-circuited the job, so that pre-existing failure stopped being reported at all.
• CORRECTED (see docs(now): retract "master has no branch protection" -- wrong endpoint #2294): corpus-ratchet is not a required check. This bullet originally read "master has no branch protection", citing GET /repos/gHashTag/t27/branches/master/protection → 404 Branch not protected. That endpoint sees only legacy branch protection and 404s for a repo protected by rulesets; the claim was wrong. Master IS protected by the active ruleset t27-master-protection — PRs required, deletion and non-fast-forward blocked, four required contexts: check-now-freshness, validate, check, check-linked-issue. corpus-ratchet is not among them (nor coverage, nor withdrawn-live), which is why all three sit red while PRs merge. ci(corpus-ratchet): run t27c's 1221 tests, which had never run on master #2291 still auto-merged at 03:57:13Z with its own corpus-ratchet run starting at 03:57:16Z — three seconds before the gate it was adding began to run — because that gate was never required. This sharpens the finding: the step was added to a workflow outside the required set, so even green it could never have blocked a merge.
• This PR's own corpus-ratchet run will fail, at Run the corpus ratchet, for the pre-existing reason above. That is the state it is being returned to, not a new regression.
• No test was edited, in either direction. bootstrap/src/math_compare.rs is compiled by nothing; its plateau test contradicts its own goldens #2290 (math_compare.rs compiled by nothing, plateau test 2.10x tighter than its own goldens) stands untouched.

[github-actions]

📓 NotebookLM Notebook linked to this PR

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[github-actions]

PR Dashboard

Generated at: 2026-08-20 04:04:52 UTC

• ci: eleven merge-critical gates were silent on stacked PRs #2169 ci: eleven merge-critical gates were silent on stacked PRs | Created: 2026-08-14 | Updated: 2026-08-14 | 5 failing / 30 total
• corpus: freeze the damage, patch one class at a time, and say where one rule stops #2161 corpus: freeze the damage, patch one class at a time, and say where one rule stops | Created: 2026-08-14 | Updated: 2026-08-20 | 0 failing / 9 total
• tri triage: five ordered classes, and blocked is tested before actionable (#2156) #2157 tri triage: five ordered classes, and blocked is tested before actionable (#2156) | Created: 2026-08-14 | Updated: 2026-08-14 | 0 failing / 17 total
• parser: nesting decides the separator, never the terminator (#2127) #2151 parser: nesting decides the separator, never the terminator (#2127) | Created: 2026-08-14 | Updated: 2026-08-14 | 2 failing / 26 total
• Unbreak FPGA CI and correct two unbacked hardware claims #2081 Unbreak FPGA CI and correct two unbacked hardware claims | Created: 2026-08-11 | Updated: 2026-08-20 | 5 failing / 27 total
• feat(igla): Wave Loop 898 — module-scope [615][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1900 feat(igla): Wave Loop 898 — module-scope [615][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• chore: civilian mesh positioning — drop drone wording (bpsk.t27) #1874 chore: civilian mesh positioning — drop drone wording (bpsk.t27) | Created: 2026-08-07 | Updated: 2026-08-07 | 2 failing / 25 total
• feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1858 feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1856 feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1854 feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1852 feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1850 feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1847 feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1844 feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1842 feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1815 feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 1 total
• feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1813 feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total
• feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1810 feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total

Summary

Status	Count
Total Open PRs	18
PRs with Failing Checks	4
PRs with All Checks Green	14
READY	7
FAILING	4
PENDING	0

Seal Status

• ⚠️ STALE -- sha256(compiler.rs)=cbbfac87dff3 != manifest seal=87e5cbd3ad94.
  The committed NMSE numbers were certified against an older compiler.rs.
  Run scripts/reseal-check.sh locally for the two-step reseal command (advisory; not a merge gate).