systematic-debugging

systematic-debugging is a skill for Claude Code from JerryLookupU/klein-harness. It costs 49 tokens per session (712 once invoked), scanned A, original, MIT.

A disciplined method for debugging software problems and finding their root cause. It requires collecting evidence, reproducing the failure, testing one explanation at a time, and verifying the fix.

In plain words
What is it for?
Investigating bugs, errors, regressions, exceptions, unexpected behavior, and failures where the cause must be established before making a fix.
Why use it?
It prevents guesses and broad code changes from being treated as a diagnosis. The method keeps the observed behavior, confirmed cause, repair, and verification clearly separate.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Investigating bugs, errors, regressions, exceptions, unexpected behavior, and failures where the cause must be established before making a fix.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jerrylookupu/klein-harness/systematic-debugging
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add JerryLookupU/klein-harness --skill systematic-debugging
Clone the repo
git clone --depth 1 https://github.com/JerryLookupU/klein-harness

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for systematic-debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/jerrylookupu/klein-harness/systematic-debugging/github.svg)](https://agentmods.dev/skills/jerrylookupu/klein-harness/systematic-debugging)
Your own site
<a href="https://agentmods.dev/skills/jerrylookupu/klein-harness/systematic-debugging"><img src="https://agentmods.dev/badge/skills/jerrylookupu/klein-harness/systematic-debugging/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for systematic-debugging

Your own site · 80×15
<a href="https://agentmods.dev/skills/jerrylookupu/klein-harness/systematic-debugging"><img src="https://agentmods.dev/badge/skills/jerrylookupu/klein-harness/systematic-debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 712 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.00712
Opus 5.5 $0.00020 $0.00285
Sonnet 5.5 $0.00010 $0.00142
Haiku 4.5 $0.00005 $0.00071

Measured 2mo ago against content hash 48b7b6415b13, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

systematic-debugging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/systematic-debugging/SKILL.md · 110 lines

What it actually says

This Skill Is For

这个 skill 用于:

  • bug 报告
  • 回归
  • error / exception / traceback
  • “为什么坏了”
  • “哪里出问题了”
  • 修复前必须先找根因的场景

一句话:

先证明原因,再决定修法。

核心纪律

  • 不先给 quick fix
  • 不同时堆多个假设
  • 不在没有证据时猜原因
  • 不在没有复现或等价失败证据时宣称已经定位
  • 不把“大改一轮看看”当作调试

最小工作流

1. 写清楚现象

至少明确:

  • 观察到的错误或异常行为
  • 期望行为
  • 影响范围
  • 当前已知输入 / 环境 / 前提

2. 先取证

优先收集:

  • 完整错误信息
  • 日志 / trace / verify 输出
  • 最近相关改动
  • 相关配置和输入数据

如果拿不到完整复现,也要先拿到最接近的失败证据。

3. 尝试复现

  • 给出最小复现步骤
  • 如果不能稳定复现,写明阻塞点和替代证据
  • 区分“真实未复现”与“尚未验证”

4. 缩成单一假设

一次只保留一个当前主假设:

  • 这个假设解释了什么现象
  • 哪条证据支持它
  • 什么最小检查可以证伪它

5. 运行最小判别测试

  • 优先选能区分假设真假的最小动作
  • 不要一上来就大面积修改代码
  • 如果测试推翻假设,回到上一步换下一个假设

6. 只有确认原因后才允许修复

修复方案必须满足:

  • 与已确认原因直接对应
  • 改动面尽可能小
  • 有明确验证方法
  • 能说明为什么不会引入更大回归

7. 修复后再验证

至少验证:

  • 原问题不再出现
  • 相关回归面没有被打坏
  • 结论有命令输出、日志或文件证据支撑

交付格式

调试结论至少包含:

  • Observed
  • Expected
  • Evidence
  • Hypothesis
  • Disprover/Test
  • Confirmed Cause 或 Still Unconfirmed
  • Minimal Fix
  • Verification

退出条件

只有在以下任一成立时才允许离开调试模式:

  • 根因已确认,且最小修复与验证路径明确
  • 当前证据不足,已清楚记录缺口和下一步取证动作

“看起来像是这里”不算完成。

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2mo ago First seen · 110 lines · 49 tokens per session scan A 48b7b6415b13

Subscribe to this mod's changes

systematic-debugging is a skill published in the GitHub repository JerryLookupU/klein-harness (10 stars, last pushed 7mo ago), licensed MIT. It adds 49 tokens to every session and 712 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

systematic-debugging compared with skills from other repositories

systematic-debugging next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
systematic-debuggingJerryLookupU/klein-harnessSkill107mo agoMITA49Claude Code
systematic-debuggingopen-metadata/OpenMetadataSkill16ktodayApache-2.0A37Claude Code
log-error-digestzebbern/claude-code-guideSkill4.7ktodayMITA71Claude Code, Codex
cwv-optimizeradobe/skillsSkill319todayApache-2.0A112Claude Code
ci-fixersipyourdrink-ltd/bernsteinSkill1.2ktodayApache-2.0A15Claude Code, Codex
diagnosing-missing-recordingsPostHog/posthogSkill41ktodaynoneA76Claude Code, Codex
loop-engineeringhuytieu/COG-second-brainSkill1.3k15d agoMITA63Claude Code