A structured method for investigating software problems such as crashes, hangs, incorrect output, memory leaks, race conditions, and slow performance. It includes debugger guidance and playbooks for common situations.

Use it to classify bugs, inspect stack traces and core dumps, find deadlocks or infinite loops, diagnose slow queries and memory growth, and investigate other runtime failures.

It replaces guesswork with a repeatable path from a symptom to reproduction, evidence, and a likely root cause.

debug-ops — Skill for Claude Code and Codex by 0xDarkMatter: A structured method for investigating software problems such as…

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/0xdarkmatter/claude-mods/debug-ops

Any agent

npx skills add 0xDarkMatter/claude-mods --skill debug-ops

Clone the repo

git clone --depth 1 https://github.com/0xDarkMatter/claude-mods

Made for: Claude Code, Codex.

Or install claude-mods, the plugin that ships this one along with the rest of its 50 skills, 3 commands, 3 agents, 4 hooks.

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/0xdarkmatter/claude-mods/debug-ops.svg)](https://agentmods.dev/skills/0xdarkmatter/claude-mods/debug-ops)

Your own site

<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/debug-ops"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/debug-ops.svg" alt="Measured on agentmods" height="20"></a>

Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,049 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.

Model	Per session	Once invoked
Fable 5	$0.00067	$0.03049
Opus 5	$0.00034	$0.01524
Sonnet 5	$0.00013	$0.00610
Haiku 4.5	$0.00007	$0.00305

Measured 3d ago against content hash 50d5b6b3ee56, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debug-ops 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 3d 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/debug-ops/SKILL.md · 282 lines

How it starts

The opening of the file, as written. The whole thing — 282 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debug Operations

Systematic debugging methodology with language-specific tooling and common scenario playbooks.

Bug Classification Decision Tree

Bug Report / Symptom
│
├─ Crash
│  ├─ Segfault / Access Violation
│  │  └─ Check: null pointer, buffer overflow, use-after-free, stack overflow
│  ├─ Panic / Fatal Error
│  │  └─ Check: assertion failure, unrecoverable state, out-of-memory
│  └─ Unhandled Exception
│     └─ Check: missing error handler, unexpected input type, network failure
│
├─ Hang
│  ├─ Deadlock
│  │  └─ Check: lock ordering, mutex contention, channel blocking
│  ├─ Infinite Loop
│  │  └─ Check: loop termination condition, counter overflow, recursive call
│  └─ Blocked I/O
│     └─ Check: network timeout, DNS resolution, disk full, file lock
│
├─ Wrong Output
│  ├─ Logic Error
│  │  └─ Check: operator precedence, boundary conditions, boolean logic
│  ├─ Data Corruption
│  │  └─ Check: concurrent mutation, encoding mismatch, truncation
│  └─ Off-by-One
│     └─ Check: loop bounds, array indexing, fence-post errors
│
├─ Performance
│  ├─ Slow Queries
│  │  └─ Check: missing index, N+1 queries, full table scan, lock wait
│  ├─ Memory Bloat
│  │  └─ Check: cache without eviction, leaked references, large allocations
│  └─ CPU Spikes
│     └─ Check: hot loops, regex backtracking, excessive GC, busy-wait
│
└─ Intermittent
   ├─ Race Condition
   │  └─ Check: shared mutable state, read-modify-write, check-then-act
   ├─ Timing-Dependent
   │  └─ Check: timeout values, clock skew, event ordering assumptions
   └─ Environment-Specific
      └─ Check: OS differences, locale, timezone, file system case sensitivity

Systematic Debugging Workflow

Six-step process from symptom to prevention:

Step 1: Reproduce

Confirm the bug exists and create a reliable reproduction. A bug you cannot reproduce is a bug you cannot confidently fix. Capture exact inputs, environment, and sequence of operations.

Step 2: Isolate

Narrow the fault to the smallest possible scope. Use binary search (git bisect, commenting out code halves), stubs, feature flags, and environment isolation to eliminate innocent code.

Read the full file on GitHub · 282 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.

3d ago First seen · 282 lines · 67 tokens per session scan A 50d5b6b3ee56

Subscribe to this mod's changes

debug-ops is a skill published in the GitHub repository 0xDarkMatter/claude-mods (32 stars, last pushed 11d ago), licensed MIT. It adds 67 tokens to every session and 3,049 once invoked, about $0.0003 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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