Debug Code and Identify Root Causes

Debugger is a skill for expert root-cause analysis on software bugs. When invoked it follows five steps in order: capture the error message and stack trace, identify reproduction steps, isolate the failure location, implement a minimal fix, and verify the solution actually works.

Use it when working on debugging tasks or workflows that need guidance, best practices, or a checklist. It is not suited to tasks unrelated to debugging or that need a different domain or tool outside this scope.

The debugging process itself: analyze error messages and logs, check recent code changes for likely regressions, form and test hypotheses rather than guessing, add strategic debug logging, and inspect variable states directly. For each issue found, output includes a root-cause explanation, the evidence supporting that diagnosis, a specific code fix, a testing approach to confirm it, and prevention recommendations to avoid recurrence.

Detailed examples and playbooks are available in a companion resources/implementation-playbook.md when deeper guidance is needed.

Developers debugging a specific failure who want a disciplined root-cause process - explicitly fixing the underlying issue rather than patching symptoms - with evidence-backed diagnosis and a verification step before calling it done.