Bug Investigation Framework

You are a senior engineer with expertise in systematic debugging. Help me investigate this bug using the scientific method.

BUG REPORT:
- Symptom: {{symptom}}
- Steps to reproduce: {{steps}}
- Expected behavior: {{expected}}
- Actual behavior: {{actual}}
- Environment: {{environment}}
- Frequency: {{frequency}}
- First occurred: {{first_occurred}}
- Error messages/logs: {{logs}}

---

## BUG INVESTIGATION REPORT

### 1. Problem Statement
[Restate the bug clearly and specifically]

**Severity assessment:**
- User impact: [Low/Medium/High/Critical]
- Frequency: [Rare/Occasional/Frequent/Always]
- Workaround exists: [Yes/No]
→ Priority: [P0/P1/P2/P3]

---

### 2. Information Gathering

**What we know:**
1. [Fact 1 - verified]
2. [Fact 2 - verified]

**What we don't know yet:**
1. [Question 1]
2. [Question 2]

**Reproduce reliability:**
- [ ] Can reproduce consistently
- [ ] Intermittent (X% of attempts)
- [ ] Cannot reproduce yet

---

### 3. Hypotheses

**Hypothesis 1: [Theory]**
- Evidence for: [What supports this]
- Evidence against: [What contradicts this]
- Test to confirm/reject: [Specific experiment]

**Hypothesis 2: [Theory]**
- Evidence for:
- Evidence against:
- Test to confirm/reject:

**Hypothesis 3: [Theory]**
- Evidence for:
- Evidence against:
- Test to confirm/reject:

**Most likely hypothesis:** [Which and why]

---

### 4. Investigation Plan

**Step 1:** [Action to narrow down]
- Expected result if Hypothesis 1 is correct: [X]
- Expected result if Hypothesis 2 is correct: [Y]

**Step 2:** [Next action based on Step 1 results]

**Step 3:** [Continue narrowing]

---

### 5. Debugging Checklist

**Basic checks:**
- [ ] Reproduce in clean environment
- [ ] Check recent changes (git blame/history)
- [ ] Review related logs
- [ ] Test with minimal reproduction case

**Common culprits to check:**
- [ ] Race condition / timing issue
- [ ] Null/undefined handling
- [ ] State management
- [ ] Cache issues (stale data)
- [ ] Environment differences
- [ ] External dependency changes
- [ ] Data format/encoding issues
- [ ] Permission/authentication issues

---

### 6. Logging & Debugging Strategy

**Add logging at:**
1. [Location] — To verify: [What we're checking]
2. [Location] — To verify: [What we're checking]

**Breakpoints to set:**
1. [Location] — Watch: [Variables/state to inspect]

---

### 7. Similar Past Issues

[Search codebase/tickets for similar bugs]
- [Similar issue 1] — Resolution: [How it was fixed]
- [Similar issue 2] — Resolution: [How it was fixed]

---

### 8. Root Cause (once found)

**The bug:**
[Clear explanation of what's actually wrong]

**Why it wasn't caught:**
[How this slipped through - for future prevention]

**The fix:**
```{{language}}
[Code fix]
```

**Verification:**
- [ ] Bug no longer reproduces
- [ ] Related functionality still works
- [ ] Added test to prevent regression

---

### 9. Prevention

**Test to add:**
```{{language}}
[Test case that would have caught this]
```

**Process improvement:**
[What could prevent similar bugs?]