Codex Debug-With-File Prompt

Overview

Enhanced evidence-based debugging with documented exploration process. Records understanding evolution, consolidates insights, and uses analysis to correct misunderstandings.

Core workflow: Explore → Document → Log → Analyze → Correct Understanding → Fix → Verify

Key enhancements over /prompts:debug:

• understanding.md: Timeline of exploration and learning
• Analysis-assisted correction: Validates and corrects hypotheses
• Consolidation: Simplifies proven-wrong understanding to avoid clutter
• Learning retention: Preserves what was learned, even from failed attempts

Target Bug

$BUG

Project Context

Run ccw spec load --category debug for known issues, workarounds, and root-cause notes.

Execution Process

Session Detection:
   ├─ Check if debug session exists for this bug
   ├─ EXISTS + understanding.md exists → Continue mode
   └─ NOT_FOUND → Explore mode

Explore Mode:
   ├─ Locate error source in codebase
   ├─ Document initial understanding in understanding.md
   ├─ Generate testable hypotheses with analysis validation
   ├─ Add NDJSON logging instrumentation
   └─ Output: Hypothesis list + await user reproduction

Analyze Mode:
   ├─ Parse debug.log, validate each hypothesis
   ├─ Use analysis to evaluate hypotheses and correct understanding
   ├─ Update understanding.md with:
   │   ├─ New evidence
   │   ├─ Corrected misunderstandings (strikethrough + correction)
   │   └─ Consolidated current understanding
   └─ Decision:
       ├─ Confirmed → Fix root cause
       ├─ Inconclusive → Add more logging, iterate
       └─ All rejected → Assisted new hypotheses

Fix & Cleanup:
   ├─ Apply fix based on confirmed hypothesis
   ├─ User verifies
   ├─ Document final understanding + lessons learned
   ├─ Remove debug instrumentation
   └─ If not fixed → Return to Analyze mode

Implementation Details

Session Setup & Mode Detection

Step 0: Determine Project Root

检测项目根目录，确保 .workflow/ 产物位置正确：

PROJECT_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || pwd)

优先通过 git 获取仓库根目录；非 git 项目回退到 pwd 取当前绝对路径。 存储为 {projectRoot}，后续所有 .workflow/ 路径必须以此为前缀。

const getUtc8ISOString = () => new Date(Date.now() + 8 * 60 * 60 * 1000).toISOString()
const projectRoot = bash('git rev-parse --show-toplevel 2>/dev/null || pwd').trim()

const bugSlug = "$BUG".toLowerCase().replace(/[^a-z0-9]+/g, '-').substring(0, 30)
const dateStr = getUtc8ISOString().substring(0, 10)

const sessionId = `DBG-${dateStr}-${bugSlug}`
const sessionFolder = `${projectRoot}/.workflow/.debug/${sessionId}`
const debugLogPath = `${sessionFolder}/debug.log`
const understandingPath = `${sessionFolder}/understanding.md`
const hypothesesPath = `${sessionFolder}/hypotheses.json`

// Auto-detect mode
const sessionExists = fs.existsSync(sessionFolder)
const hasUnderstanding = sessionExists && fs.existsSync(understandingPath)
const logHasContent = sessionExists && fs.existsSync(debugLogPath) && fs.statSync(debugLogPath).size > 0

const mode = logHasContent ? 'analyze' : (hasUnderstanding ? 'continue' : 'explore')

if (!sessionExists) {
  bash(`mkdir -p ${sessionFolder}`)
}

Explore Mode

Step 1.1: Locate Error Source

// Extract keywords from bug description
const keywords = extractErrorKeywords("$BUG")

// Search codebase for error locations
const searchResults = []
for (const keyword of keywords) {
  const results = Grep({ pattern: keyword, path: ".", output_mode: "content", "-C": 3 })
  searchResults.push({ keyword, results })
}

// Identify affected files and functions
const affectedLocations = analyzeSearchResults(searchResults)

Step 1.2: Document Initial Understanding

Create understanding.md:

# Understanding Document

**Session ID**: ${sessionId}
**Bug Description**: $BUG
**Started**: ${getUtc8ISOString()}

---

## Exploration Timeline

### Iteration 1 - Initial Exploration (${timestamp})

#### Current Understanding

Based on bug description and initial code search:

- Error pattern: ${errorPattern}
- Affected areas: ${affectedLocations.map(l => l.file).join(', ')}
- Initial hypothesis: ${initialThoughts}

#### Evidence from Code Search

${searchResults.map(r => `
**Keyword: "${r.keyword}"**
- Found in: ${r.results.files.join(', ')}
- Key findings: ${r.insights}
`).join('\n')}

#### Next Steps

- Generate testable hypotheses
- Add instrumentation
- Await reproduction

---

## Current Consolidated Understanding

${initialConsolidatedUnderstanding}

Step 1.3: Generate Hypotheses

Analyze the bug and generate 3-5 testable hypotheses:

// Hypothesis generation based on error pattern
const HYPOTHESIS_PATTERNS = {
  "not found|missing|undefined|未找到": "data_mismatch",
  "0|empty|zero|registered": "logic_error",
  "timeout|connection|sync": "integration_issue",
  "type|format|parse": "type_mismatch"
}

function generateHypotheses(bugDescription, affectedLocations) {
  // Generate targeted hypotheses based on error analysis
  // Each hypothesis includes:
  // - id: H1, H2, ...
  // - description: What might be wrong
  // - testable_condition: What to log
  // - logging_point: Where to add instrumentation
  // - evidence_criteria: What confirms/rejects it
  return hypotheses
}

Save to hypotheses.json:

{
  "iteration": 1,
  "timestamp": "2025-01-21T10:00:00+08:00",
  "hypotheses": [
    {
      "id": "H1",
      "description": "Data structure mismatch - expected key not present",
      "testable_condition": "Check if target key exists in dict",
      "logging_point": "file.py:func:42",
      "evidence_criteria": {
        "confirm": "data shows missing key",
        "reject": "key exists with valid value"
      },
      "likelihood": 1,
      "status": "pending"
    }
  ]
}

Step 1.4: Add NDJSON Instrumentation

For each hypothesis, add logging at the specified location:

Python template:

# region debug [H{n}]
try:
    import json, time
    _dbg = {
        "sid": "{sessionId}",
        "hid": "H{n}",
        "loc": "{file}:{line}",
        "msg": "{testable_condition}",
        "data": {
            # Capture relevant values here
        },
        "ts": int(time.time() * 1000)
    }
    with open(r"{debugLogPath}", "a", encoding="utf-8") as _f:
        _f.write(json.dumps(_dbg, ensure_ascii=False) + "\n")
except: pass
# endregion

JavaScript/TypeScript template:

// region debug [H{n}]
try {
  require('fs').appendFileSync("{debugLogPath}", JSON.stringify({
    sid: "{sessionId}",
    hid: "H{n}",
    loc: "{file}:{line}",
    msg: "{testable_condition}",
    data: { /* Capture relevant values */ },
    ts: Date.now()
  }) + "\n");
} catch(_) {}
// endregion

Step 1.5: Output to User

## Hypotheses Generated

Based on error "$BUG", generated {n} hypotheses:

{hypotheses.map(h => `
### ${h.id}: ${h.description}
- Logging at: ${h.logging_point}
- Testing: ${h.testable_condition}
- Evidence to confirm: ${h.evidence_criteria.confirm}
- Evidence to reject: ${h.evidence_criteria.reject}
`).join('')}

**Debug log**: ${debugLogPath}

**Next**: Run reproduction steps, then come back for analysis.

Analyze Mode

Step 2.1: Parse Debug Log

// Parse NDJSON log
const entries = Read(debugLogPath).split('\n')
  .filter(l => l.trim())
  .map(l => JSON.parse(l))

// Group by hypothesis
const byHypothesis = groupBy(entries, 'hid')

// Validate each hypothesis
for (const [hid, logs] of Object.entries(byHypothesis)) {
  const hypothesis = hypotheses.find(h => h.id === hid)
  const latestLog = logs[logs.length - 1]

  // Check if evidence confirms or rejects hypothesis
  const verdict = evaluateEvidence(hypothesis, latestLog.data)
  // Returns: 'confirmed' | 'rejected' | 'inconclusive'
}

Step 2.2: Analyze Evidence and Correct Understanding

Review the debug log and evaluate each hypothesis:

1. Parse all log entries
2. Group by hypothesis ID
3. Compare evidence against expected criteria
4. Determine verdict: confirmed | rejected | inconclusive
5. Identify incorrect assumptions from previous understanding
6. Generate corrections

Step 2.3: Update Understanding with Corrections

Append new iteration to understanding.md:

### Iteration ${n} - Evidence Analysis (${timestamp})

#### Log Analysis Results

${results.map(r => `
**${r.id}**: ${r.verdict.toUpperCase()}
- Evidence: ${JSON.stringify(r.evidence)}
- Reasoning: ${r.reason}
`).join('\n')}

#### Corrected Understanding

Previous misunderstandings identified and corrected:

${corrections.map(c => `
- ~~${c.wrong}~~ → ${c.corrected}
  - Why wrong: ${c.reason}
  - Evidence: ${c.evidence}
`).join('\n')}

#### New Insights

${newInsights.join('\n- ')}

${confirmedHypothesis ? `
#### Root Cause Identified

**${confirmedHypothesis.id}**: ${confirmedHypothesis.description}

Evidence supporting this conclusion:
${confirmedHypothesis.supportingEvidence}
` : `
#### Next Steps

${nextSteps}
`}

---

## Current Consolidated Understanding (Updated)

${consolidatedUnderstanding}

Step 2.4: Update hypotheses.json

{
  "iteration": 2,
  "timestamp": "2025-01-21T10:15:00+08:00",
  "hypotheses": [
    {
      "id": "H1",
      "status": "rejected",
      "verdict_reason": "Evidence shows key exists with valid value",
      "evidence": {...}
    },
    {
      "id": "H2",
      "status": "confirmed",
      "verdict_reason": "Log data confirms timing issue",
      "evidence": {...}
    }
  ],
  "corrections": [
    {
      "wrong_assumption": "...",
      "corrected_to": "...",
      "reason": "..."
    }
  ]
}

Fix & Verification

Step 3.1: Apply Fix

Based on confirmed hypothesis, implement the fix in the affected files.

Step 3.2: Document Resolution

Append to understanding.md:

### Iteration ${n} - Resolution (${timestamp})

#### Fix Applied

- Modified files: ${modifiedFiles.join(', ')}
- Fix description: ${fixDescription}
- Root cause addressed: ${rootCause}

#### Verification Results

${verificationResults}

#### Lessons Learned

What we learned from this debugging session:

1. ${lesson1}
2. ${lesson2}
3. ${lesson3}

#### Key Insights for Future

- ${insight1}
- ${insight2}

Step 3.3: Cleanup

Remove debug instrumentation by searching for region markers:

const instrumentedFiles = Grep({
  pattern: "# region debug|// region debug",
  output_mode: "files_with_matches"
})

for (const file of instrumentedFiles) {
  // Remove content between region markers
  removeDebugRegions(file)
}

Session Folder Structure

{projectRoot}/.workflow/.debug/DBG-{date}-{slug}/
├── debug.log           # NDJSON log (execution evidence)
├── understanding.md    # Exploration timeline + consolidated understanding
└── hypotheses.json     # Hypothesis history with verdicts

Understanding Document Template

# Understanding Document

**Session ID**: DBG-xxx-2025-01-21
**Bug Description**: [original description]
**Started**: 2025-01-21T10:00:00+08:00

---

## Exploration Timeline

### Iteration 1 - Initial Exploration (2025-01-21 10:00)

#### Current Understanding
...

#### Evidence from Code Search
...

#### Hypotheses Generated
...

### Iteration 2 - Evidence Analysis (2025-01-21 10:15)

#### Log Analysis Results
...

#### Corrected Understanding
- ~~[wrong]~~ → [corrected]

#### Analysis Results
...

---

## Current Consolidated Understanding

### What We Know
- [valid understanding points]

### What Was Disproven
- ~~[disproven assumptions]~~

### Current Investigation Focus
[current focus]

### Remaining Questions
- [open questions]

Debug Log Format (NDJSON)

Each line is a JSON object:

{"sid":"DBG-xxx-2025-01-21","hid":"H1","loc":"file.py:func:42","msg":"Check dict keys","data":{"keys":["a","b"],"target":"c","found":false},"ts":1734567890123}

Field	Description
sid	Session ID
hid	Hypothesis ID (H1, H2, ...)
loc	Code location
msg	What's being tested
data	Captured values
ts	Timestamp (ms)

Iteration Flow

First Call (BUG="error"):
   ├─ No session exists → Explore mode
   ├─ Extract error keywords, search codebase
   ├─ Document initial understanding in understanding.md
   ├─ Generate hypotheses
   ├─ Add logging instrumentation
   └─ Await user reproduction

After Reproduction (BUG="error"):
   ├─ Session exists + debug.log has content → Analyze mode
   ├─ Parse log, evaluate hypotheses
   ├─ Update understanding.md with:
   │   ├─ Evidence analysis results
   │   ├─ Corrected misunderstandings (strikethrough)
   │   ├─ New insights
   │   └─ Updated consolidated understanding
   ├─ Update hypotheses.json with verdicts
   └─ Decision:
       ├─ Confirmed → Fix → Document resolution
       ├─ Inconclusive → Add logging, document next steps
       └─ All rejected → Assisted new hypotheses

Output:
   ├─ {projectRoot}/.workflow/.debug/DBG-{date}-{slug}/debug.log
   ├─ {projectRoot}/.workflow/.debug/DBG-{date}-{slug}/understanding.md (evolving document)
   └─ {projectRoot}/.workflow/.debug/DBG-{date}-{slug}/hypotheses.json (history)

Error Handling

Situation	Action
Empty debug.log	Verify reproduction triggered the code path
All hypotheses rejected	Generate new hypotheses based on disproven assumptions
Fix doesn't work	Document failed fix attempt, iterate with refined understanding
>5 iterations	Review consolidated understanding, escalate with full context
Understanding too long	Consolidate aggressively, archive old iterations to separate file

Consolidation Rules

When updating "Current Consolidated Understanding":

1. Simplify disproven items: Move to "What Was Disproven" with single-line summary
2. Keep valid insights: Promote confirmed findings to "What We Know"
3. Avoid duplication: Don't repeat timeline details in consolidated section
4. Focus on current state: What do we know NOW, not the journey
5. Preserve key corrections: Keep important wrong→right transformations for learning

Bad (cluttered):

## Current Consolidated Understanding

In iteration 1 we thought X, but in iteration 2 we found Y, then in iteration 3...
Also we checked A and found B, and then we checked C...

Good (consolidated):

## Current Consolidated Understanding

### What We Know
- Error occurs during runtime update, not initialization
- Config value is None (not missing key)

### What Was Disproven
- ~~Initialization error~~ (Timing evidence)
- ~~Missing key hypothesis~~ (Key exists)

### Current Investigation Focus
Why is config value None during update?

Key Features

Feature	Description
NDJSON logging	Structured debug log with hypothesis tracking
Hypothesis generation	Analysis-assisted hypothesis creation
Exploration documentation	understanding.md with timeline
Understanding evolution	Timeline + corrections tracking
Error correction	Strikethrough + reasoning for wrong assumptions
Consolidated learning	Current understanding section
Hypothesis history	hypotheses.json with verdicts
Analysis validation	At key decision points

When to Use

Best suited for:

• Complex bugs requiring multiple investigation rounds
• Learning from debugging process is valuable
• Team needs to understand debugging rationale
• Bug might recur, documentation helps prevention

---

Now execute the debug-with-file workflow for bug: $BUG