Macro-4 Delete-Fast Failure Modes — R2-B2 (2026-06-19)

Date: 2026-06-19 · Workstream: R2-B2-MACRO-4-STAGING-WORKBENCH-IO-CONTRACT-TD-ENTRY-GATE-2026-06-19 (Deliverable 40 of 90) · Editorial revision: rev1 Class: delete-fast failure modes · READ-ONLY · NON-ENACTING · NON-AUTHORIZING · NO write performed.

Metadata convention. Editorial revision (rev1) only. Storage revision/content_length authoritative at read time.

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0. Status and non-authorization

STATUS: PASS — engineering / design-only. The ways delete-fast can fail and why each disqualifies the design. Engineering PASS ≠ authority PASS. Default: HOLD.

1. Purpose

Enumerate delete-fast failure modes so a future build is designed against them.

2. Sources / evidence read

Bad-input/delete-fast plan §6 (F-OPEN-8/9)/§8; pilot-slice staging IO contract §9 (BAD-15); inspect-producer §10. Main process, no reader-agents.

3. Accepted baseline (carried)

If delete-fast leaves any candidate/evidence behind (F-OPEN-9), or a candidate reaches a production field (F-OPEN-8), the design is rejected.

4. Evidence / analysis — failure modes (DFM)

#	Failure mode	Why disqualifying
DFM-1	Residue: a candidate output survives disposal	F-OPEN-9 / BAD-15 — surface not total
DFM-2	Cross-run bleed: disposal removes the wrong run's artifacts	rollback unit not bounded
DFM-3	Production leak: a candidate reached a production field	F-OPEN-8 — load-bearing isolation failure
DFM-4	Downstream certify: a staging run triggered a production certify	B4 must never see staging candidates
DFM-5	Dangling reference: a pointer/edge survives the deleted unit	no-leftover-references violated
DFM-6	Silent disposal: deletion claimed without DFE evidence	PASS-without-evidence (F-OPEN-10)

5. Contract / requirement / matrix / result

Any DFM-n observed ⇒ the staging design is rejected (fail-closed). These modes are the adversarial targets for a future delete-fast verification; no test is run here.

6. Owner-gated future work

Testing against these modes requires a built surface — Owner-gated; forbidden now.

7. What remains unresolved

All modes are conceptual until a producer + surface exist.

8. Ready for GPT/Codex review

Yes — Codex should add any delete-fast failure mode omitted.