Debug
If topology=multi-module (triage announcement or coordinator spec/plan declaration), read ../references/multi-module.md. Investigate read-only across repos; fix inside the task's registered module only; defer commits until integration passes.
- Reproduce. Minimal deterministic repro. No repro → no fix.
- Root-cause. Ask "why" until one cause explains all symptoms. Symptoms != cause.
- Regression test first (red), then fix at the root (green). Use
tdd.
Don't
- Guess. Read the code and the full error.
- Change two things at once.
- Stop at the first plausible cause.
3 failed hypotheses → re-read from scratch. Done = repro + regression test + root cause named + green.