sd0xdev Bug Fix Skill
Trigger
- Keywords: bug, issue, fix, error, broken, failing
When NOT to Use
- New feature development (use feature-dev)
- Just want to understand code (use code-explore)
- Pure test-only tasks without feature changes (use
/codex-test-reviewdirectly)
Prohibited Actions
❌ git add | git commit | git push — per @rules/git-workflow.md
This skill fixes bugs but does not commit. /precommit is a quality gate only. To commit, the user must invoke /smart-commit --execute separately.
Workflow
Investigate → Locate → Fix → Test + Review → Precommit Gate
│ │ │ │ │
▼ ▼ ▼ ▼ ▼
gh issue Grep Edit /verify /precommit
/git-investigate Read tests /codex-test-review
/codex-review-fast
Phase 1: Investigation
Before fixing: if the bug maps to a feature under docs/features/, read
docs/features/<key>/intent-<key>.md when it exists — a fix that contradicts one of its INV-*
invariants or Non-goals stops and asks the user (cite the line). No identifiable feature →
nothing to load; proceed.
| Source | Action |
|---|---|
| GitHub Issue | gh issue view <number> |
| Error message | Grep("error message") |
| Code history | /git-investigate |
Output root cause analysis:
- Problem location:
src/<module>/<file>:<line> - Root cause:
- Impact scope:
Phase 2: Fix
| Principle | Description |
|---|---|
| Minimal changes | Only modify what is necessary |
| No new issues | Confirm changes don't affect other features |
| Design preserved | Choose the smallest root-cause fix that keeps current responsibilities. If the fix moves a boundary or adds an abstraction, say which shape you chose and why — "direct fix; existing design retained" is the expected common answer |
Phase 3: Add Regression Test ⚠️
Follow @rules/testing.md for conventions (AAA, naming, evidence model).
Follow @rules/testing-project.md for project-specific overrides.
Bug fixes must have tests at the corresponding level:
| Bug Type | Required | Recommended |
|---|---|---|
| Logic error | Unit | - |
| Service issue | Unit | Integration |
| API issue | Integration | E2E |
| Cross-service/data flow | Integration | E2E |
| User flow | E2E | - |
Phase 4: Verify + Review
Step 1: Run tests
/verify → all tests pass?
Yes → Step 2
No → fix failures → re-run /verify
Step 2: Test adequacy review (mandatory for code changes)
/codex-test-review → ✅ Tests sufficient?
Yes → Step 3
No → close gaps (Step 2a) → /codex-test-review --continue <threadId>
Step 2a: Gap closure
| Gap Type | Remediation |
|---|---|
| Unit test missing | /codex-test-gen → write tests → /verify |
| Integration/E2E missing | /post-dev-test → write tests → /verify |
Step 3: Code review (auto-loop)
/codex-review-fast → ✅ Ready?
Yes → Precommit Gate
No → fix issues → re-run /codex-review-fast (auto-loop)
Freshness rule
If code changes after the latest ✅ Tests sufficient gate (e.g., fixes from code review), rerun /verify then /codex-test-review --continue <threadId> before proceeding to precommit gate.
Review Loop
MUST re-review after fix until PASS (per @rules/auto-loop.md)
Fix → Review → Issues found → Fix again → ... → ✅ Pass → Next step
Doc Sync
Doc Sync is governed by @rules/auto-loop.md (behavior-layer rule). After precommit pass, triggers conditionally when changes map to docs/features/.
Output
## Bug Fix Report
- **Root cause**: <analysis>
- **Fix**: <description of changes>
- **Regression test**: <test result>
- **Gate**: ✅ Fixed / ⛔ Needs further investigation
Verification Checklist
- Root cause identified and documented
- Regression test written at appropriate level
- All tests pass (
/verify) - Test adequacy reviewed (
/codex-test-review) - Code review passed (
/codex-review-fast✅ Ready) - Precommit passed (
/precommit✅ All Pass) - No
git add/commit/pushexecuted
Examples
Input: Fix issue #123 - calculation error
Action: gh issue view → locate → fix → write Unit Test → /verify → /codex-test-review → /codex-review-fast → /precommit
Input: API returning 500 error
Action: Grep error → read code → fix → write Integration Test → /verify → /codex-test-review → /codex-review-fast → /precommit