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diagnosing-bugs SKILL.md skillA

diagnosing-bugs from dayfinggg/openai-codex-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add dayfinggg/openai-codex-agent-skills/diagnosing-bugs@git:20261029.276ae81

Pins git:20261029.276ae81 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: dayfinggg/openai-codex-agent-skills
Path: codex/skills/diagnosing-bugs/SKILL.md
Versions recorded: 4
Latest version: git:20261029.276ae81, committed Oct 29, 2026
First version recorded: Jul 26, 2026
Size: 8,724 bytes
Repository stars: 8
License: MIT

Diagnose a difficult reproducible bug or performance regression through a feedback loop, competing hypotheses, and regression proof.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

Read [local host integration](../.shared/host-integration.md) before applying this imported workflow.

# Diagnosing Bugs

A discipline for hard bugs. Skip phases only when explicitly justified.

When exploring the codebase, read `GLOSSARY.md` (if it exists) to get a clear mental model of the relevant modules, and check ADRs in the area you're touching.

## Redact

This skill has you show commands, outputs and captured artifacts. **Redact every secret first**: write `<REDACTED>` in its place. Build loops against env vars, so the credential stays in the environment rather than in what you show. Captured artifacts carry auth headers: quote only the lines that carry the signal.

If the redacted output is not enough to diagnose the bug, say so and ask the user.

## Phase 1: Build a feedback loop

**This is the skill.** Everything else is mechanical. If you have a **tight** pass/fail signal for the bug (one that goes red on _this_ bug), you will find the cause; bisection, hypothesis-testing, and instrumentation all just consume it. If you don't have one, no amount of staring at code will save you.

Spend disproportionate effort here. **Be aggressive. Be creative. Refuse to give up.**
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add dayfinggg/openai-codex-agent-skills/diagnosing-bugs@sha256:ca68236e717eef25

The line at the top of this page pins the label git:20261029.276ae81, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_osyqaftam2b352x2.svg)](https://markdownregistry.com/a/art_osyqaftam2b352x2)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 4 versions of this file, between Jul 26, 2026 and Oct 29, 2026, about one every 32 days.

version	committed	commit	size	audit
git:20261029.276ae81 latest	2026-10-29	276ae81	8,724 B	A	view · diff
git:20260801.8234b5f	2026-08-01	8234b5f	6,370 B	A	view · diff
git:20260727.971ea79	2026-07-27	971ea79	6,440 B	A	view · diff
git:20260726.812376b	2026-07-26	812376b	6,124 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (8724 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

dayfinggg/openai-codex-agent-skills · 8 stars · license MIT · pushed 2026-11-01 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_osyqaftam2b352x2
GET https://markdownregistry.com/api/v1/resolve?ref=dayfinggg/openai-codex-agent-skills/diagnosing-bugs
GET https://markdownregistry.com/api/v1/blob/ca68236e717eef25c229c0e4ce7aed3643f5692153b3e4b33e08a86748371547

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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