diagnose

Diagnoses bugs and performance regressions through a structured reproduce-hypothesise-fix workflow.

Updated May 7, 2026
One-click install
npx skills add https://github.com/jecg2804/HumanOS --skill diagnose-jecg2804
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: diagnose
Source: https://github.com/jecg2804/HumanOS/tree/main/.claude/skills/diagnose
Command: npx skills add https://github.com/jecg2804/HumanOS --skill diagnose-jecg2804

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) components.

What problem does it solve? Hard bugs and performance regressions resist casual debugging: staring at code rarely finds the cause. This Skill enforces a disciplined six-phase loop — build a feedback loop, reproduce, hypothesise, instrument, fix with a regression test, and clean up — so bugs are found systematically instead of by luck. ## Core Features & Use Cases - Feedback-loop construction: Ten ranked strategies for building a fast, deterministic pass/fail signal, from failing tests and curl scripts to headless browser runs, bisection harnesses, and differential loops. - Falsifiable hypothesis ranking: Generates 3–5 ranked hypotheses with explicit predictions before any testing, avoiding single-hypothesis anchoring. - Tagged instrumentation and cleanup: Every debug log gets a unique [DEBUG-xxxx] prefix so cleanup is a single grep, and the post-mortem phase records the confirmed root cause in the commit message. - Use Case: A user reports that an export button intermittently throws an error. The Skill builds a reproduction loop (using the included human-in-the-loop bash template if needed), reproduces the failure, tests ranked hypotheses one variable at a time, and lands a fix guarded by a regression test. ## Quick Start Ask the agent to diagnose the bug you are experiencing and describe the exact symptom, error message, or performance regression you observed.

Frequently Asked Questions about diagnose

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I debug an intermittent or non-deterministic bug?▼

Raise the reproduction rate instead of chasing a clean repro: loop the trigger 100 times, parallelise, add stress, narrow timing windows, or inject sleeps. A bug that fails 50% of the time is debuggable; one that fails 1% of the time is not, so keep increasing the rate until hypotheses can be tested against it.

How to diagnose a performance regression in a web app?▼

Establish a baseline measurement first using a timing harness, performance.now(), a profiler, or a query plan, then bisect to find the cause. Logs are usually the wrong tool for performance work; measure first and fix second, changing one variable at a time.

What should I do when a bug cannot be reproduced locally?▼

Stop and say so explicitly rather than guessing. List what you tried, then ask for environment access, a captured artifact such as a HAR file, log dump, or screen recording, or permission to add temporary production instrumentation before forming hypotheses.

When should a regression test be written for a bug fix?▼

Write the regression test before the fix, but only when a correct seam exists where the test exercises the real bug pattern as it occurs at the call site. If no correct seam exists, that absence is itself a finding about the codebase architecture and should be flagged.

Why generate multiple hypotheses before testing a bug?▼

Generating 3–5 ranked falsifiable hypotheses prevents anchoring on the first plausible idea. Each hypothesis must state a testable prediction, and showing the ranked list to the user lets domain knowledge re-rank it cheaply before any testing time is spent.