Systematic Debugging

When to Use

• A bug, error, exception, or crash needs investigation
• Something is "not working" and the cause is unclear
• A test is failing and the reason isn't obvious
• Unexpected behavior needs troubleshooting in any language or framework

Core Workflow

Follow these five phases sequentially. Do not skip ahead to fixing before completing isolation and tracing.

Phase 1: Reproduce

Establish a reliable way to trigger the bug before doing anything else.

1. Read the full error message, stack trace, and logs — note exact text, line numbers, and error codes
2. Create a minimal reproduction case that triggers the issue consistently
3. Record the exact steps, inputs, and environment that cause the failure