$ca-debug — root-cause investigation

Investigates a defect, anomaly, or unexpected behavior whose cause is not yet known. Separates investigation from implementation: no code is modified while debugging. Describe the symptom with enough fidelity that another operator could reproduce it — observed behavior, reproduction steps (or intermittent-trigger profile), and environment. Vague descriptions ("it's flaky") are rejected; the orchestrator asks for clarification before routing.

If the cause is already known and a regression test is already named, invoke $ca-fix directly.

Routes to

The debug skill (routines/debug/SKILL.md) — five gated phases: symptom capture, hypothesis generation, evidence gathering, root-cause decision, handoff. Phase 4 forces one named exit:

• (a) Confirmed bug → $ca-fix, carrying the confirmed bug statement, cited evidence, and a named regression test obligation tied to the minimal repro.
• (b) Behavior/design ambiguity → $ca-adr, with the ambiguity statement and evidence ledger, authored only with explicit user attribution.
• (c) No-action close — symptom and rationale appended to <project-root>/.codearbiter/open-tasks.md.

A real finding that is out of scope for those exits is marked inline [NEEDS-TRIAGE] and the investigation continues.

When NOT to use

• Known bug with a named regression test → $ca-fix directly.
• Design discussion with no failing behavior → $ca-adr.
• New feature → $ca-feature.
• A general "why does it behave this way" question with no defect → $ca-btw.
• Re-entry from inside $ca-fix or $ca-adr → exit that command first (routing-cycle prevention).

Hard gate

MUST NOT modify any code during Phases 1–5 — code changes belong to $ca-fix. MUST exit Phase 4 with exactly one of (a)/(b)/(c). Exit (a) MUST carry a regression test obligation. Exit (b) MUST obtain user attribution before any $ca-adr. MUST NOT promote INCONCLUSIVE evidence to CONFIRMED without a cited source.