Debug
Not this skill: building a known feature or applying an approved plan → implement. If the user is in Cursor Debug mode, follow that mode; otherwise use this checklist.
Checklist
- Symptoms — errors, logs, repro steps, expected vs actual
- Repro matrix — browser/OS, data state, auth role, feature flags when relevant
- Trace — follow the path from trigger to failure
- Layer — UI, client state, server/API, data store, config, external service
- Pinpoint — root cause with file + function (and line when useful)
- Fix proposal — smallest change that fixes the cause, not symptoms only
- Implement — only if the user asked to fix, or after they approve
Rules
- Prefer evidence (stack traces, failing tests) over guesses
- Use
git bisector commit range when user gives a regression window - For backend: check logs, request/response, DB queries, env/config before patching
- Do not change unrelated code “while you’re here”
- If not reproducible, state what you tried and what remains unknown
After root cause is known and the user wants the fix built, continue with implement.
Related skills
- test — reproduce via failing tests
- ui-browser-check — UI-layer symptoms in a running app
- ci — failure only on CI