Debugging Patterns

Overview

Debugging is the systematic process of identifying, analyzing, and resolving defects in software. This skill should be invoked when encountering unexpected behavior, errors, or failures in code. Effective debugging requires a methodical approach rather than random trial-and-error. Invoke this skill when fixing production bugs, troubleshooting test failures, or analyzing runtime errors.

Core Principles

• Reproducibility: A bug that cannot be reproduced cannot be reliably fixed. Always aim to create a consistent reproduction case.
• Hypothesis-Driven: Form testable hypotheses about the root cause before making changes. Never guess.
• Isolation: Isolate variables by removing noise and focusing on the minimal code path that reproduces the issue.
• Observability: Use logs, breakpoints, and debugging tools to observe system state rather than assuming.

Preparation Checklist

• Gather the exact error message, stack trace, and relevant logs
• Identify the environment where the bug occurs (dev, staging, production)
• Ensure you have access to debugging tools appropriate for the language/framework
• Understand the expected behavior vs. actual behavior