debug-systematically

name	debug-systematically
description	Use this skill when diagnosing a bug, unexpected behavior, test failure, or any situation where code does not behave as expected. Follow a structured debugging process instead of randomly changing code.
category	coding

Debug Systematically

Process:

1. Reproduce the bug with the smallest possible input.
2. Isolate — narrow down which component/function causes it.
3. Hypothesize — form a specific, falsifiable hypothesis.
4. Test — verify or disprove the hypothesis with a minimal experiment.
5. Fix — address the root cause, not just the symptom.
6. Verify — re-run the failing test and related tests.

Useful tools: print/logging, pdb/ipdb, unit tests, git bisect.

Anti-patterns:

• Changing multiple things at once and not knowing what fixed it.
• Ignoring related test failures.
• Commenting out code instead of understanding it.