Use when the user says diagnose or debug this, or reports something broken, throwing, failing, or slow.
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
# 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.**
### Ways to construct one, in roughly this order
…
The line at the top of this page pins the label git:20261006.f349c21, 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.
GET https://markdownregistry.com/api/v1/artifacts/art_bsx5itwo77fi4x5b
GET https://markdownregistry.com/api/v1/resolve?ref=kunanonj/ai-skills-hub/diagnosing-bugs
GET https://markdownregistry.com/api/v1/blob/3cc67527b27218066fdce7754a7c9b8e1017714408b173ce5b9a1f0f1d19644e
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.
kunanonj/ai-skills-hub · plugins/superstacks/skills/code-review/SKILL.md · Use when reviewing a branch, PR, or WIP since a commit, tag, or merge-base. Two-axis Standards and Spec review via…
kunanonj/ai-skills-hub · plugins/superstacks/skills/domain-modeling/SKILL.md · Use when discussing codebase terminology, writing or editing a GLOSSARY.md, or recording or editing an ADR.
kunanonj/ai-skills-hub · plugins/superstacks/skills/gardening/SKILL.md · Use when finding small maintenance work. One concern per PR, each with a verify command and a small diff budget.
kunanonj/ai-skills-hub · plugins/superstacks/skills/grill-with-docs/SKILL.md · Use when grilling a plan or design that should also produce ADRs and a glossary as you go.
kunanonj/ai-skills-hub · plugins/superstacks/skills/grilling/SKILL.md · Use when the user wants to stress-test a plan, decision, or idea, or uses any grill trigger phrases.
kunanonj/ai-skills-hub · plugins/superstacks/skills/how/SKILL.md · Use for how-does-X-work walkthroughs, placement, ownership, and layering questions before changing code.
kunanonj/ai-skills-hub · plugins/superstacks/skills/intake-triage/SKILL.md · Use when a coordinator has a batch of bug reports, feedback, or alerts. Deduplicate, group, score two-way vs one-way…
kunanonj/ai-skills-hub · plugins/superstacks/skills/interrogate/SKILL.md · Use for interrogate, adversarial review, multi-model review, challenge this, stress test this code, or find blind spots.
kunanonj/ai-skills-hub · plugins/superstacks/skills/mistake-to-constraint/SKILL.md · Use when a mistake repeats. Encode it as the strongest guard — type or runtime, lint, test, directory convention, then…
kunanonj/ai-skills-hub · plugins/superstacks/skills/sample-review/SKILL.md · Use when sampling recently merged PRs against repo standards and CONSTRAINTS.md. Propose environment tightenings, not…
kunolu/640-skills · sbtd-workflow-onboard/assets/external-skills/stable/skills/diagnosing-bugs/SKILL.md · Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports…
mxyhi/ok-skills · diagnosing-bugs/SKILL.md · Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports…
asymmetric-al/core · .agents/skills/diagnosing-bugs/SKILL.md · Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports…
oyadotai/oya-browser · .agents/skills/diagnosing-bugs/SKILL.md · This skill should be used when diagnosing a reported bug, intermittent failure, stuck operation, or performance…
oyadotai/oya-browser · .claude/skills/diagnosing-bugs/SKILL.md · This skill should be used when diagnosing a reported bug, intermittent failure, stuck operation, or performance…
jellydn/my-ai-tools · skills/diagnosing-bugs/SKILL.md · Build a tight, red-capable feedback loop before diagnosing failures, then minimize, test ranked hypotheses, and lock…
jellydn/my-ai-tools · configs/amp/plugins/my-ai-tools-skills/skills/diagnosing-bugs/SKILL.md · Build a tight, red-capable feedback loop before diagnosing failures, then minimize, test ranked hypotheses, and lock…