---
phase: 17.1
slug: python-vtab-crash-investigation
status: draft
nyquist_compliant: false
wave_0_complete: false
created: 2026-03-08
---

# Phase 17.1 — Validation Strategy

> Per-phase validation contract for feedback sampling during execution.

---

## Test Infrastructure

| Property | Value |
|----------|-------|
| **Framework** | Python + just test-all |
| **Config file** | Justfile + Makefile |
| **Quick run command** | `just test-ducklake-ci` |
| **Full suite command** | `just test-all` |
| **Estimated runtime** | ~30 seconds |

---

## Sampling Rate

- **After every task commit:** Run `just test-ducklake-ci`
- **After every plan wave:** Run `just test-all`
- **Before `/gsd:verify-work`:** Full suite must be green
- **Max feedback latency:** 30 seconds

---

## Per-Task Verification Map

| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | File Exists | Status |
|---------|------|------|-------------|-----------|-------------------|-------------|--------|
| CRASH-01 | 01 | 1 | Reproduce crash | manual/script | `python3 test/integration/test_vtab_crash.py` | No - W0 | pending |
| CRASH-02 | 01 | 1 | Identify root cause | manual/debugger | `lldb python3 -- test/integration/test_vtab_crash.py` | No - W0 | pending |
| CRASH-03 | 02 | 2 | Fix prevents crash | integration | `just test-ducklake-ci` | Yes | pending |
| CRASH-04 | 02 | 2 | No CLI regression | integration | `just test-sql` | Yes | pending |
| CRASH-05 | 02 | 2 | No Rust regression | unit | `cargo test` | Yes | pending |

*Status: pending · green · red · flaky*

---

## Wave 0 Requirements

- [ ] `test/integration/test_vtab_crash.py` — minimal Python crash reproduction script
- [ ] Crash reproduction confirmed (or investigation pivots)

---

## Manual-Only Verifications

| Behavior | Requirement | Why Manual | Test Instructions |
|----------|-------------|------------|-------------------|
| Crash root cause identification | CRASH-02 | Requires debugger analysis of crash signal/backtrace | Run under lldb, capture bt at crash point |

---

## Validation Sign-Off

- [ ] All tasks have `<automated>` verify or Wave 0 dependencies
- [ ] Sampling continuity: no 3 consecutive tasks without automated verify
- [ ] Wave 0 covers all MISSING references
- [ ] No watch-mode flags
- [ ] Feedback latency < 30s
- [ ] `nyquist_compliant: true` set in frontmatter

**Approval:** pending
