| name | diagnose |
| description | Structured debugging loop for exercise tests or build failures. Reproduce → isolate → hypothesize → fix → verify. |
Diagnose a Failure
You are debugging a test failure or build error in this project. Follow the structured loop — do NOT jump to a fix without reproducing first.
Loop
1. Reproduce
Run the failing command and capture the exact error:
pnpm test
pnpm test:rust
pnpm test:go
pnpm test:python
pnpm build
2. Isolate
Narrow down to the smallest failing unit:
- Which test file?
- Which test case?
- Which assertion?
3. Hypothesize
State your hypothesis in one sentence before changing any code.
4. Instrument
Add minimal logging or assertions to confirm/deny your hypothesis. Do NOT change production code yet.
5. Fix
Apply the minimal fix. Change as little as possible.
6. Verify
Run the full test suite, not just the failing test:
pnpm test && pnpm build
If it still fails, return to step 1 with what you learned.
7. Regression Test
If the bug was non-trivial, add a test that would have caught it.
