debugging

debugging is a skill for Claude Code, Codex from nimadorostkar/Claude-Skills-collection. It costs 42 tokens per session (974 once invoked), scanned A, original, MIT.

A method for finding the real cause of a software bug through reproduction, isolation, measurement, and proof. It covers ordinary failures as well as intermittent, concurrent, and performance-related problems.

In plain words
What is it for?
Use it to reproduce flaky failures, compare working and failing environments, investigate code-history changes, inspect races and deadlocks, analyse CPU or memory profiles, and add regression tests.
Why use it?
It reduces speculative code changes that hide symptoms without fixing the defect. It produces evidence for the root cause and checks that the problem does not return.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to reproduce flaky failures, compare working and failing environments, investigate code-history changes, inspect races and deadlocks, analyse CPU or memory profiles, and add regression tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/nimadorostkar/claude-skills-collection/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 nimadorostkar/Claude-Skills-collection --skill debugging
Clone the repo
git clone --depth 1 https://github.com/nimadorostkar/Claude-Skills-collection

Made for: Claude Code, Codex.

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 debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/debugging/github.svg)](https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/debugging)
Your own site
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/debugging"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/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 debugging

Your own site · 80×15
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/debugging"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 974 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00042 $0.00974
Opus 5 $0.00021 $0.00487
Sonnet 5 $0.00008 $0.00195
Haiku 4.5 $0.00004 $0.00097

Measured 10d ago against content hash ab68fc581ea1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, 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 10d 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/development/debugging/SKILL.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugging

Purpose

Find the actual cause of a defect, not a change that makes the symptom disappear. Debugging is a search problem, and the method is binary search over hypotheses.

When to Use

  • A test fails and the reason is not obvious from the assertion.
  • Production behavior differs from local behavior.
  • An intermittent or timing-dependent failure.
  • A performance regression with no obvious cause.
  • A bug that "came back" after being fixed.

Capabilities

  • Deterministic reproduction, including of flaky failures.
  • Bisection over code history, input space, and configuration.
  • Instrumentation: strategic logging, breakpoints, tracing, core dumps.
  • Concurrency debugging: race detectors, deadlock analysis, lock ordering.
  • Performance debugging: CPU and allocation profiles, flame graphs.

Inputs

  • The failure: error message, stack trace, failing test, or observed behavior.
  • The last known-good state, if any.
  • Environment differences between where it fails and where it does not.

Outputs

  • A reproduction that fails reliably.
  • A stated root cause, with the evidence that proves it.
  • A fix, plus a regression test that fails without the fix.

Workflow

  1. Reproduce — Reduce to the smallest input and shortest path that still fails. If you cannot reproduce it, you cannot verify a fix. For flaky failures, run in a loop until you have a failure rate.
  2. Read the evidence — Read the entire stack trace, including the parts you have seen before. Read the actual error, not the one you assume it is.
  3. Form one hypothesis — State it as a falsifiable claim: "the cache returns a stale value because the invalidation runs before the write commits."
  4. Test the hypothesis — Add instrumentation that would distinguish true from false. Do not change behavior yet.
  5. Bisect — If no hypothesis survives, bisect. git bisect over commits; comment out halves of the input; disable half the config.
  6. Prove the cause — You have the cause when you can turn the bug on and off at will.
  7. Fix and regress — Write the failing test first, then fix, then confirm the test passes and the rest still do.

Read the full file on GitHub · 90 lines

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. 10d ago First seen · 90 lines · 42 tokens per session scan A ab68fc581ea1

Subscribe to this mod's changes

debugging is a skill published in the GitHub repository nimadorostkar/Claude-Skills-collection (26 stars, last pushed 22d ago), licensed MIT. It adds 42 tokens to every session and 974 once invoked, about $0.0002 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 2026-08-30.

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