What is systematic-debugging?

A step-by-step method for finding the underlying cause of bugs, failed tests, build failures, and other unexpected behaviour.

It helps investigate error messages, reproduction steps, stack traces, environment details, and code before proposing a fix.

It prevents repeated guess-and-check fixes that may hide the symptom while creating new problems.

systematic-debugging — Skill for Claude Code by yeaight7

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 yeaight7/agent-powerups --skill systematic-debugging

Clone the repo

git clone --depth 1 https://github.com/yeaight7/agent-powerups

Made for: Claude Code.

Or install debugging-diagnostics, the plugin that ships this one along with the rest of its 8 skills, 4 commands, 2 agents.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/yeaight7/agent-powerups/systematic-debugging/github.svg)](https://agentmods.dev/skills/yeaight7/agent-powerups/systematic-debugging)

Your own site

<a href="https://agentmods.dev/skills/yeaight7/agent-powerups/systematic-debugging"><img src="https://agentmods.dev/badge/skills/yeaight7/agent-powerups/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/yeaight7/agent-powerups/systematic-debugging"><img src="https://agentmods.dev/badge/skills/yeaight7/agent-powerups/systematic-debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,453 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.

Model	Per session	Once invoked
Fable 5.1	$0.00022	$0.01453
Opus 5.5	$0.00009	$0.00581
Sonnet 5.5	$0.00004	$0.00291
Haiku 4.5	$0.00002	$0.00145

Measured 1mo ago against content hash ed7795a18f7a, 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 1mo ago.

The scan reads SKILL.md. This mod also ships 2 executable files (examples/condition-based-waiting-example.ts, references/find-polluter.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

plugins/debugging-diagnostics/skills/systematic-debugging/SKILL.md · 156 lines

How it starts

The opening of the file, as written. The whole thing — 156 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Find the root cause of any bug before attempting a fix. Random fixes waste time and create new bugs. Symptom fixes are failure.

Core principle: ALWAYS find root cause before attempting fixes.

When to Use

Use for ANY technical issue:

Test failures
Bugs in production
Unexpected behavior
Performance problems
Build failures
Integration issues

Use this especially when:

Under time pressure (emergencies make guessing tempting)
"Just one quick fix" seems obvious
You've already tried multiple fixes
Previous fix didn't work
You don't fully understand the issue

Do not skip when:

Issue seems simple (simple bugs have root causes too)
You're in a hurry (rushing guarantees rework)
Someone wants it fixed immediately (systematic is faster than thrashing)

Inputs

Bug description or error message.
Stack trace or reproduction steps.
Environment context (OS, versions, recent changes).
Access to the codebase and test suite.

Workflow

You MUST complete each phase before proceeding to the next.

Phase 1: Root Cause Investigation

Before attempting ANY fix:

Read error messages carefully — Don't skip past errors or warnings. Read stack traces completely. Note line numbers, file paths, error codes.
Reproduce consistently — Can you trigger it reliably? What are the exact steps? If not reproducible: gather more data, don't guess.
Check recent changes — What changed that could cause this? Git diff, recent commits, new dependencies, config changes, environmental differences.

Gather evidence in multi-component systems — When the system has multiple components (CI → build → signing, API → service → database):

For EACH component boundary:
  - Log what data enters the component
  - Log what data exits the component
  - Verify environment/config propagation
  - Check state at each layer

Run once to gather evidence showing WHERE it breaks.
Then analyze to identify the failing component.
Then investigate that specific component.

Read the full file on GitHub · 156 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

1mo ago First seen · 156 lines · 22 tokens per session scan A ed7795a18f7a

Subscribe to this mod's changes

systematic-debugging is a skill published in the GitHub repository yeaight7/agent-powerups (6 stars, last pushed 19d ago), licensed Apache-2.0. It adds 22 tokens to every session and 1,453 once invoked, about $0.0001 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 2026-09-14.

Debugging agent agent-skill agent-skills agents gemini-cli-extension plugin