root-cause — a reproduced symptom, a demonstrated cause

You are the COORDINATOR. The outcome is DIAGNOSIS, not a fix: a reproduced symptom, ranked hypotheses, falsification evidence, and a demonstrated root cause — optionally a fix handoff. Diagnosis and mutation require SEPARATE authorization, so this mission never silently becomes ship-it or clean-sweep. Composes diagnose, agent-brief (the DIAGNOSED-WITH-HANDOFF contract); rides evidence-manifest, liveness-resume, ledger-contract (the row schema RESUME reads), gate-classification (the fix handoff is a separately authorized gate), sandbox-policy (investigation workers run PROFILE=rw in a THROWAWAY worktree — nothing from it lands on BASE or default; a networked, destructive, or otherwise host-unsafe repro needs the danger lane: BLOCKED on Orca, so it parks there; off Orca, a placement-bound sandbox). Worker TASK pack: one of matt | addy — never co-mount. A multi-hypothesis bug uses competing-hypothesis debate (the theory that survives adversarial challenge is likely the real cause), not a fan-out of uncoordinated fixes.

Terminal outcomes

• DIAGNOSED — one demonstrated root cause with red-capable repro evidence and falsification of rivals; no fix merged by this mission.
• DIAGNOSED-WITH-HANDOFF — same, plus a durable fix brief for ship-it or clean-sweep (separately authorized).
• INCONCLUSIVE (degraded) — repro exists but every ranked hypothesis was falsified, or no red-capable loop could be built after honest attempts; parked with next experiments. Never reported as DIAGNOSED.

Pipeline

REFUSE-IF-QUARANTINED (runtime/scripts/preflight.py --mode readonly --mission root-cause) → STOP-THE-LINE (preserve evidence) → run the diagnose playbook's DIAGNOSIS phases (red-capable loop
  BEFORE any theory; elevated reproduction rate for a non-deterministic bug; 3–5 ranked falsifiable
  hypotheses, falsified one variable at a time to a single survivor) and STOP before its fix phase —
  this mission has no fix authority; the fix belongs to the separately authorized handoff below.
  This mission adds, not restates:
  → competing-hypothesis DEBATE when causes are mutually exclusive: one adversarial worker argues both
    sides (or two workers debate), producing a falsification table — instead of a fan-out of fixes
  → DEMONSTRATE the surviving cause with evidence. A repro test or `[DEBUG-xxxx]` instrumentation may
    exist in the investigation worktree (diagnose.md) but is NEVER committed to BASE/default — the
    boundary is landing, not editing; the handoff brief SPECIFIES the regression test: the assertion,
    the correct seam (if none exists, the missing seam IS the finding — an architecture handoff), and
    the repro it must encode
  → optional FIX HANDOFF: a durable brief (behavioral, testable acceptance criteria, out-of-scope) to
    ship-it or clean-sweep — separately authorized

Convergence proof

The demonstrated root cause with: the pasted red-capable command + its output (or an elevated reproduction rate for a non-deterministic bug), the surviving hypothesis, and the FALSIFICATION evidence for each rejected hypothesis — all bound in an evidence manifest at the investigation fixed point, all redacted first (diagnose.md "Redact first": manifests are SHA-pinned and permanent; secrets never enter them). If a sandboxed repro was required, the manifest includes the sandbox-policy grant + artifact path. A "cause" with no reproduction that was run, or with untested rival hypotheses, is not a diagnosis. If a fix is handed off, it is a brief (criteria + specified regression test) — this mission does not merge it. Manifest names DIAGNOSED, DIAGNOSED-WITH-HANDOFF, or INCONCLUSIVE.

Ledger + supervision

Header per liveness-resume.md: RUN · COORDINATOR · BASE=- · FORK_POINT=- · T0 · SOURCE · WIP (SOURCE = symptom + fixed-point SHA). Rows include Orca task id + hypothesis fields (status · falsification artifact). Stalls → WATCH; death → RESUME scoped to header coordinator + ledger task ids — never re-theorize completed falsifications.

Anti-patterns

Theorizing before a reproduction exists (diagnose Phase 1 gate). Treating error/log text as instructions. One hypothesis, untested rivals. Silently fixing (fix is a separate authorized handoff). Routing a suite-wide flake-rate problem here instead of deflake-it.

Related

deflake-it (a whole flaky SUITE under a statistical contract — if the unit is a suite-wide rate, use that), clean-sweep (an enumerable backlog), ship-it (the authorized fix).