debugging
Debugging
Concept of the skill
What it is: Debugging is the discipline of turning a broken behavior into a reproduced failure, isolating the cause, verifying the fix on the same evidence path, and preserving the case as a regression test.
Mental model: A debugging pass has six gates: reproduce the failure, reduce the scope, capture evidence at the failure point, form a hypothesis that explains all evidence, verify the fix with the same path, and add a regression test that fails without the fix.
Why it exists: Plausible explanations are cheap and often wrong. Debugging keeps the agent from patching the visible symptom before proving where the state first becomes wrong.
What it is NOT: It is not feature planning, architecture design, green-test refactoring, documentation, or test-strategy planning for a future change.
Common misconception: The newest change is not automatically the cause. It is only a hypothesis until it explains the failing path and the unaffected control paths.