debugger

allowed-tools	["Read","Write","Grep","Glob","Bash"]
description	Use when debugging bugs to find root causes, or after 3 failed fix attempts to stop and document state.
name	debugger
trigger	버그 디버깅, 오류 원인 찾기, 에러 추적, root cause, unexpected behavior, bug investigation, 3 strike rule, 가설 검증, hypothesis testing, meta debugging, self code review, debug memory search, 과거 디버그 기록, systematic investigation, 변수 변경 테스트, 편향 피하기, 3 회 실패 후 중단, fresh session, 상태 기록, root cause 분석, 증빙 기반 디버깅

Quick Reference

• 3-Strike Rule: 3회 실패 시 즉시 중단 → STATE.md 기록 → fresh session 권장
• Memory First: 조사 전 .hxsk/memories/ 검색으로 과거 유사 사례 확인
• Valid Hypothesis: 반증 가능해야 함 (구체적 원인 명시, 추측 금지)
• One Variable: 한 번에 하나의 변수만 변경하여 테스트 및 문서화
• Persist Findings: 원인 발견 시 root-cause, 배제 시 debug-eliminated 저장

Core Philosophy

User = Reporter, AI = Investigator

User knows: what they expected, what happened, error messages, when it started.

User does NOT know (don't ask): what's causing it, which file, what the fix is.

Ask about experience. Investigate the cause yourself.

Meta-Debugging: Your Own Code

When debugging code you wrote, you're fighting your own mental model.

• Treat your code as foreign — Read it as if someone else wrote it
• Question your design decisions — Your implementations are hypotheses
• Admit your mental model might be wrong — Code behavior is truth
• Prioritize code you touched — Modified lines are prime suspects

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Foundation Principles

• What do you know for certain? Observable facts, not assumptions
• What are you assuming? "This library should work this way" — verified?
• Strip away everything you think you know. Build understanding from facts.

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Cognitive Biases to Avoid

Bias	Trap	Antidote
Confirmation	Only look for supporting evidence	Actively seek disconfirming evidence
Anchoring	First explanation becomes anchor	Generate 3+ hypotheses before investigating
Availability	Recent bugs → assume similar cause	Treat each bug as novel
Sunk Cost	Spent 2 hours, keep going	Every 30 min: "Would I still take this path?"

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Systematic Investigation

Change one variable: Make one change, test, observe, document, repeat.

Complete reading: Read entire functions, not just "relevant" lines.

Embrace not knowing: "I don't know" = good (now you can investigate). "It must be X" = dangerous.

Debugging Techniques + Hypothesis Testing + When to Restart → references/debugging-techniques.md

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3-Strike Rule

After 3 failed fix attempts:

1. STOP the current approach
2. Document what was tried in DEBUG.md
3. Summarize to STATE.md
4. Recommend fresh session with new context

A fresh context often immediately sees what polluted context cannot.

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Debug Memory

Before any investigation, search past context:

Grep(pattern: "{symptom}", path: ".hxsk/memories/", output_mode: "files_with_matches")

Persist findings after each session (elimination, root cause, blocked state).

Debug Memory 전체 프로토콜 → references/debug-memory.md

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관련 스킬

• REQUIRED: empirical-validation — 수정 후 경험적 증거로 검증
• REQUIRED: memory-protocol — 근본 원인, 배제된 가설을 메모리에 저장
• RECOMMENDED: impact-analysis — 수정 전 영향 범위 분석

Scripts

(없음 — Bash, Read, Grep 등 에이전트 네이티브 도구로 직접 수행)

Iron Laws

NO CONTINUE_AFTER_3_FAILURES WITHOUT STATE_RECORDING_AND_FRESH_SESSION FIRST NO HYPOTHESIS_FORMULATION WITHOUT FALSIFIABILITY FIRST NO CHANGE_WITHOUT_ISOLATING_SINGLE_VARIABLE FIRST NO DIAGNOSIS_WITHOUT_COMPLETE_FUNCTION_READING FIRST NO INVESTIGATION_WITHOUT_PAST_MEMORY_SEARCH FIRST NO ASKING_USER_FOR_ROOT_CAUSE FIRST NO INVESTIGATION_WITHOUT_3_PLUS_HYPOTHESES FIRST NO DEBUGGING_WITHOUT_TREATING_CODE_AS_FOREIGN FIRST NO SESSION_END_WITHOUT_MEMORY_PERSISTENCE FIRST