debugging

A method for finding software bugs by reproducing them, collecting evidence, and tracing symptoms back to their root cause.

In plain words
What is it for?
Use it to investigate errors, crashes, incorrect or intermittent behavior, and failures involving logs, databases, networks, or recent code changes.
Why use it?
It prevents guesswork and broad changes that may hide the real failure or create new ones.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/soden46/engineer-flow/debugging
Any agent
npx skills add soden46/engineer-flow --skill debugging
Clone the repo
git clone --depth 1 https://github.com/soden46/engineer-flow

Made for: Claude Code, Codex.

Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 227 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00018 $0.00227
Opus 5 $0.00009 $0.00113
Sonnet 5 $0.00004 $0.00045
Haiku 4.5 $0.00002 $0.00023

Measured 2d ago against content hash f7626eb85027, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 2d 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/engineer-flow/core/debugging/SKILL.md · 50 lines

What it actually says

debugging

Use this skill for failures, exceptions, incorrect behavior, intermittent bugs, and root-cause analysis.

Principles

Reproduce before changing code when practical.

Separate:

  • symptom
  • trigger
  • root cause

Collect evidence from relevant:

  • errors
  • logs
  • inputs
  • state
  • recent changes
  • traces
  • database behavior
  • network behavior

Reduce the problem to the smallest useful reproduction.

Avoid broad speculative changes.

Once root cause is identified:

  1. make the smallest correct fix
  2. add regression protection where useful
  3. verify nearby behavior
  4. remove temporary debugging instrumentation

Do not hide failures merely by suppressing exceptions or logs.

Adaptation

Use project evidence to determine the actual language, framework, runtime, and existing conventions.

When stack-specific implementation guidance is needed, prefer project evidence, native framework or language mechanisms, and relevant user-installed specialist skills. Technology-specific guidance must not redefine or weaken the core engineering requirement.

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. 2d ago First seen · 50 lines · 18 tokens per session scan A f7626eb85027

Subscribe to this mod's changes

debugging is a skill published in the GitHub repository soden46/engineer-flow (3 stars, last pushed 4d ago), licensed MIT. It adds 18 tokens to every session and 227 once invoked, about $0.0001 per session on Opus 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 2026-08-31.

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