root-cause-analysis

Root Cause Analysis

Diagnose failures without blame, identify durable system levers, and produce corrective actions that prevent recurrence. A valid RCA explains BOTH the creation path (why the bad condition existed) and the escape path (why it reached the user/repo/system despite controls). The goal is the smallest durable system change that would have prevented, detected, contained, or reversed the failure — not assigning fault.

Boundary (read first — avoids overlap)

• debug-loop / debugging-memory = live, find-and-fix THIS bug now (iterative investigate→fix→verify).
• root-cause-analysis (this) = blameless post-failure analysis → durable lever + actuator + regression artifact + spread check. It runs after the fix, or on a class/pattern, and is what debug-loop's report phase and recursive-retrospective §8 should invoke instead of carrying their own mini-RCA.

The three prompts (modular)

1. General RCA — references/root-cause-analysis/01-rca.md: any failure. Tiered L0 (log) / L1 (mini) / L2 (full).
2. Agentic Coding RCA — references/root-cause-analysis/02-agentic-rca.md: extension of Prompt 1 for AI-coding-agent failures (attribution gate, agentic failure modes, loop-fix vs code-repair). It is Prompt 1 + deltas, not a restatement.
3. Mini-RCA — references/root-cause-analysis/03-mini-rca.md: lightweight L1 for low-risk issues.
4. Judge — references/root-cause-analysis/04-judge.md: independent evaluator with a mandatory verification gate (a claim is FACT only if checked against source). NEW vs the source suite — closes the "labeled FACT but never verified" gap.

Hardening applied (vs the source RCA suite)

• Level↔schema binding. L0 = 3 fields; L1 = Mini-RCA; only L2 uses the full schema. The full output schema does NOT apply to L0/L1 (the source "use this exact structure" fought the tiering).
• Density governor. Omit a section that yields no signal; never pad an empty table. Shorter-with-signal beats exhaustive.
• Verify-before-FACT. A causal claim may be tagged FACT only if independently checked against its cited source this session; otherwise INFERENCE/ASSUMPTION.
• Tool-bound spread check. "Where else could this happen?" is a grep/NavGator-impact job, not prose — run the scan and cite hits.
• Owner optional in agent contexts. The owner of a durable fix is often a gate/hook, not a person; actuator + regression artifact are the real closure, not owner/due-date.
• Mini-RCA tree-escalation. If a second independent contributor appears, escalate from the linear four-whys to the L2 causal map.

Native strengths preserved (the reason this suite is worth keeping)

• Creation path + escape path duality (control existed? fired? ignored/misread/bypassed/too weak?).
• Action Strength Hierarchy (eliminate > substitute > forcing-function > standardize > automate-detection > checklist > train/doc). "Be more careful" / docs-as-sole-fix is banned unless risk is low and no stronger lever is feasible.
• Lever + Actuator (where the fix lands vs what makes it fire) — the dormant-fix antidote.
• Banned closures: human error · agent error · be more careful · edge case · quirk · cosmetic · one-off · works now · "fixed in code" without prevention.
• Regression artifact proving old-behavior-fails / new-behavior-passes.
• First Attribution Gate (agentic): check task/context/loop/tool/codebase/verification/review BEFORE blaming the agent.

Model tiering

• L2 RCA + the judge are Frontier-tier (Fable); judge MUST run independent of the analysis author. Frontier-unavailable → Opus fallback, never Code tier.
• L0/L1 can run at the executor tier.

Output homes

• Corrective actions with a memory/rule target route through the canonical memory_writer.py; regression artifacts (tests/evals/policy/checklist) commit in-repo.