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diagnose

Reproduce, minimize, hypothesize, instrument, and validate bug fixes.

1|Updated Jun 9, 2026
Search Tags:#debugging#instrumentation#reproduction#regression-testing#hypothesising#minimisation
One-click install
npx skills add https://github.com/prestarius/jet-skills-stack --skill diagnose-prestarius
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: diagnose
Source: https://github.com/prestarius/jet-skills-stack/tree/main/skills/diagnose
Command: npx skills add https://github.com/prestarius/jet-skills-stack --skill diagnose-prestarius

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Debug methodically — reproduce, minimise, hypothesise, instrument, fix, then add a regression test. Use whenever the user is chasing a bug, says "why is this failing", or has a flaky/mysterious failure.

Core Features & Use Cases

  • Reproduce deterministically to establish a reliable failure.
  • Minimise the failing case to the smallest repro, isolating root causes.
  • Hypothesise with testable explanations and instrument to gather evidence.
  • Implement a fix aligned to the root cause and create a regression test.
  • Follow robust guardrails to avoid patching symptoms without proof.

Quick Start

Reproduce the bug with a deterministic input and observe the failing behavior.

Frequently Asked Questions about diagnose

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

FAQPage Schema
How do I debug a flaky or mysterious failure methodically?▼

To debug a flaky failure methodically, first reproduce the bug deterministically, then minimise the failing case, hypothesise root causes, instrument for evidence, and validate fixes with regression tests.

What is the best way to isolate a root cause from a complex bug report?▼

The best way to isolate a root cause is minimising the failing case to the smallest reproducible input, which narrows down variables and clarifies the exact conditions triggering the failure.

How do I create a deterministic reproduction for a bug that only fails sometimes?▼

Creating a deterministic reproduction requires identifying and controlling the specific inputs and environmental conditions causing the intermittent failure, ensuring the bug triggers reliably every time.

Why does my code fail, and how do I avoid patching symptoms instead of the root cause?▼

Your code fails due to an underlying defect, and to avoid patching symptoms you must form verifiable hypotheses, instrument the code to gather evidence, and confirm the root cause before fixing.

When should I add regression testing during a debugging session?▼

You should add regression testing immediately after implementing a fix aligned to the root cause, ensuring the regression test validates the specific bug reproduction and prevents future reintroductions.

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