Debugger Detective Skill

Name: debugger-detective
Rating: 76
Author: MadAppGang

This skill uses claudemem's context command for debugging and root cause analysis.

Why Claudemem Works Better for Debugging

Task	claudemem	Native Tools
Trace backwards	`callers` shows call chain	Manual tracing
Trace forwards	`callees` shows dependencies	Manual tracing
Full context	`context` gives both directions	Multiple reads
Root cause	Call chain reveals origin	Trial and error

Primary commands:

•claudemem --agent context <name> - Full call chain (callers + callees)
•claudemem --agent callers <name> - Trace back to error source
•claudemem --agent callees <name> - Trace forward from failure point

Debugger Detective Skill

Version: 3.3.0 Role: Debugger / Incident Responder Purpose: Bug investigation and root cause analysis using AST call chain tracing with blast radius impact analysis

Role Context

You are investigating this codebase as a Debugger. Your focus is on:

•Error origins - Where exceptions are thrown
•Call chains - How execution flows to the failure point
•State mutations - What changed the data before failure
•Root causes - The actual source of problems (not just symptoms)
•Impact radius - What else might be affected

Why `context` is Perfect for Debugging

The context command shows you:

•Symbol definition = Where the buggy code is
•Callers = How we got here (trace backwards)
•Callees = What happens next (trace forward)
•Full call chain = Complete picture for root cause analysis

Debugger-Focused Commands (v0.3.0)

Find the Bug Location

bash

# Find the function mentioned in error
claudemem --agent symbol authenticate
# Get full context (callers + callees)
claudemem --agent context authenticate```

### Trace Back to Source (callers)

```bash
# Who called this function? (trace backwards)
claudemem --agent callers authenticate
# Follow the chain backwards
claudemem --agent callers LoginControllerclaudemem --agent callers handleRequest```

### Trace Forward to Effect (callees)

```bash
# What does this function call? (trace forward)
claudemem --agent callees authenticate
# Find where state changes happen
claudemem --agent callees updateSession```

### Blast Radius Analysis (v0.4.0+ Required)

```bash
# After finding the bug, check what else is affected
IMPACT=$(claudemem --agent impact buggyFunction)

if [ -z "$IMPACT" ] || echo "$IMPACT" | grep -q "No callers"; then
  echo "No static callers - bug is isolated (or dynamically called)"
else
  echo "$IMPACT"
  echo ""
  echo "This shows:"
  echo "- Direct callers (immediately affected)"
  echo "- Transitive callers (potentially affected)"
  echo "- Complete list for testing after fix"
fi

Use for:

•Post-fix verification (test all impacted code)
•Regression prevention (know what to test)
•Incident documentation (impact scope)

Limitations: Event-driven/callback architectures may have callers not visible to static analysis.

Error Origin Hunting

bash

# Map error handling code
claudemem --agent map "throw error exception"
# Find specific error types
claudemem --agent symbol AuthenticationError
# Who throws this error?
claudemem --agent callers AuthenticationError```

### State Mutation Tracking

```bash
# Find where state changes
claudemem --agent map "set state update mutate"
# Find the mutation function
claudemem --agent symbol updateUserState
# Who calls this mutation?
claudemem --agent callers updateUserState```

## PHASE 0: MANDATORY SETUP

### Step 1: Verify claudemem v0.3.0

```bash
which claudemem && claudemem --version
# Must be 0.3.0+

Step 2: If Not Installed → STOP

Use AskUserQuestion (see ultrathink-detective for template)

Step 3: Check Index Status

bash

# Check claudemem installation and index
claudemem --version && ls -la .claudemem/index.db 2>/dev/null

Step 3.5: Check Index Freshness

Before proceeding with investigation, verify the index is current:

bash

# First check if index exists
if [ ! -d ".claudemem" ] || [ ! -f ".claudemem/index.db" ]; then
  # Use AskUserQuestion to prompt for index creation
  # Options: [1] Create index now (Recommended), [2] Cancel investigation
  exit 1
fi

# Count files modified since last index
STALE_COUNT=$(find . -type f \( -name "*.ts" -o -name "*.tsx" -o -name "*.js" -o -name "*.jsx" -o -name "*.py" -o -name "*.go" -o -name "*.rs" \) \
  -newer .claudemem/index.db 2>/dev/null | grep -v "node_modules" | grep -v ".git" | grep -v "dist" | grep -v "build" | wc -l)
STALE_COUNT=$((STALE_COUNT + 0))  # Normalize to integer

if [ "$STALE_COUNT" -gt 0 ]; then
  # Get index time with explicit platform detection
  if [[ "$OSTYPE" == "darwin"* ]]; then
    INDEX_TIME=$(stat -f "%Sm" -t "%Y-%m-%d %H:%M" .claudemem/index.db 2>/dev/null)
  else
    INDEX_TIME=$(stat -c "%y" .claudemem/index.db 2>/dev/null | cut -d'.' -f1)
  fi
  INDEX_TIME=${INDEX_TIME:-"unknown time"}

  # Get sample of stale files
  STALE_SAMPLE=$(find . -type f \( -name "*.ts" -o -name "*.tsx" \) \
    -newer .claudemem/index.db 2>/dev/null | grep -v "node_modules" | grep -v ".git" | head -5)

  # Use AskUserQuestion (see template in ultrathink-detective)
fi

Step 4: Index if Needed

bash

claudemem index

Workflow: Bug Investigation (v0.3.0)

Phase 1: Locate the Symptom

bash

# Find where the error appears
claudemem --agent map "error message keywords"
# Or find the specific function
claudemem --agent symbol failingFunction```

### Phase 2: Get Full Context

```bash
# Get callers + callees in one command
claudemem --agent context failingFunction```

### Phase 3: Trace Backwards (Find Root Cause)

```bash
# For each caller, check if it's the source
claudemem --agent callers caller1claudemem --agent callers caller2
# Keep tracing until you find the root

Phase 4: Verify the Chain

bash

# Once you suspect a root cause, verify the path
claudemem --agent callees suspectedRoot
# Does it lead to the symptom?

Phase 5: Check Impact

bash

# What else calls the buggy code?
claudemem --agent callers buggyFunction
# These are all potentially affected

Output Format: Bug Investigation Report

1. Symptom Summary

code

┌─────────────────────────────────────────────────────────┐
│                    BUG INVESTIGATION                     │
├─────────────────────────────────────────────────────────┤
│  Symptom: User sees "undefined" in profile name          │
│  Location: src/components/Profile.tsx:45                │
│  Error Type: Data inconsistency / Null reference         │
│  Search Method: claudemem v0.3.0 (AST call chain)       │
└─────────────────────────────────────────────────────────┘

2. Call Chain Trace

code

❌ SYMPTOM: undefined rendered
   └── src/components/Profile.tsx:45
       └── user.name is undefined

↑ CALLER CHAIN (trace backwards):
   └── useUser hook (src/hooks/useUser.ts:23)
       ↑
   └── fetchUser API (src/api/user.ts:67)
       ↑
   └── userMapper (src/mappers/user.ts:12)
       ↑
🔍 ROOT CAUSE FOUND HERE

3. Root Cause Analysis

code

🔍 ROOT CAUSE IDENTIFIED:

Location: src/mappers/user.ts:12
Problem: Field name mismatch

API Response:       { fullName: "John Doe" }
Mapper Expects:     { full_name: "..." }
Result:             name = undefined

Evidence:
- callees of fetchUser → userMapper
- callers of userMapper → useUser → Profile
- Complete chain verified via context command

4. Impact Analysis

code

⚠️ OTHER AFFECTED CODE:

claudemem --agent callers userMapper shows:
  - useUser hook (main app)
  - useAdmin hook (admin panel)
  - tests/user.test.ts

All 3 locations may have the same bug!

Scenarios

Scenario: Null Pointer Exception

bash

# Step 1: Find where undefined is used
claudemem --agent map "undefined null"
# Step 2: Get context of the failing function
claudemem --agent context renderProfile
# Step 3: Trace backwards through callers
claudemem --agent callers getUserData
# Step 4: Find where null was introduced
claudemem --agent callees fetchUser```

### Scenario: Race Condition

```bash
# Step 1: Find async operations
claudemem --agent map "async await promise"
# Step 2: Find shared state
claudemem --agent symbol sharedState
# Step 3: Who reads it?
claudemem --agent callers sharedState
# Step 4: Who writes it?
claudemem --agent callees updateState```

### Scenario: Incorrect Behavior

```bash
# Step 1: Find the function with wrong behavior
claudemem --agent symbol calculateTotal
# Step 2: What does it depend on?
claudemem --agent callees calculateTotal
# Step 3: Who provides input?
claudemem --agent callers calculateTotal```

## Result Validation Pattern

After EVERY claudemem command, validate results:

### Context Validation for Debugging

When tracing call chains:

```bash
CONTEXT=$(claudemem --agent context failingFunction)
EXIT_CODE=$?

# Check for failure
if [ "$EXIT_CODE" -ne 0 ]; then
  DIAGNOSIS=$(claudemem status 2>&1)
  # Use AskUserQuestion
fi

# Validate all sections present
if ! echo "$CONTEXT" | grep -q "\[symbol\]"; then
  # Missing symbol section - function not found
  # Use AskUserQuestion: Reindex, Different name, or Cancel
fi

if ! echo "$CONTEXT" | grep -q "\[callers\]"; then
  # Missing callers - may be entry point or index issue
  # Entry points (API handlers, main) have 0 callers - this is expected
fi

if ! echo "$CONTEXT" | grep -q "\[callees\]"; then
  # Missing callees - may be leaf function or index issue
  # Leaf functions (console.log, throw) have 0 callees - this is expected
fi

Empty Results Handling

bash

CALLERS=$(claudemem --agent callers suspectedBug)

# 0 callers could mean:
# 1. Entry point (main, API handler) - expected
# 2. Dead code - use dead-code command (v0.4.0+)
# 3. Dynamically called - check for import(), eval, reflection

if echo "$CALLERS" | grep -qi "error\|not found"; then
  # Actual error vs no callers
  # Use AskUserQuestion
fi

FALLBACK PROTOCOL

CRITICAL: Never use grep/find/Glob without explicit user approval.

If claudemem fails or returns irrelevant results:

•STOP - Do not silently switch tools
•DIAGNOSE - Run claudemem status
•REPORT - Tell user what happened
•ASK - Use AskUserQuestion for next steps

typescript

// Fallback options (in order of preference)
AskUserQuestion({
  questions: [{
    question: "claudemem bug investigation failed or found no call chain. How should I proceed?",
    header: "Debugging Issue",
    multiSelect: false,
    options: [
      { label: "Reindex codebase", description: "Run claudemem index (~1-2 min)" },
      { label: "Try different function name", description: "Search for related functions" },
      { label: "Use grep (not recommended)", description: "Traditional search - loses call chain tracing" },
      { label: "Cancel", description: "Stop investigation" }
    ]
  }]
})

See ultrathink-detective skill for complete Fallback Protocol documentation.

Anti-Patterns

Anti-Pattern	Why Wrong	Correct Approach
`grep "error"`	No call relationships	`claudemem --agent context func`
Read random files	No direction	Trace callers/callees systematically
Fix symptom only	Bug returns	Trace to root cause with `callers`
Skip impact check	Miss related bugs	ALWAYS check all `callers`
`cmd \| head/tail`	Hides call chain context	Use full output or `--max-depth`

Output Truncation Warning

╔══════════════════════════════════════════════════════════════════════════════╗ ║ ║ ║ ❌ Anti-Pattern 7: Truncating Claudemem Output ║ ║ ║ ║ FORBIDDEN (any form of output truncation): ║ ║ → BAD: claudemem --agent map "query" | head -80 ║ ║ → BAD: claudemem --agent callers X | tail -50 ║ ║ → BAD: claudemem --agent search "x" | grep -m 10 "y" ║ ║ → BAD: claudemem --agent map "q" | awk 'NR <= 50' ║ ║ → BAD: claudemem --agent callers X | sed '50q' ║ ║ → BAD: claudemem --agent search "x" | sort | head -20 ║ ║ → BAD: claudemem --agent map "q" | grep "pattern" | head -20 ║ ║ ║ ║ CORRECT (use full output or built-in limits): ║ ║ → GOOD: claudemem --agent map "query" ║ ║ → GOOD: claudemem --agent search "x" -n 10 ║ ║ → GOOD: claudemem --agent map "q" --tokens 2000 ║ ║ → GOOD: claudemem --agent search "x" --page-size 20 --page 1 ║ ║ → GOOD: claudemem --agent context Func --max-depth 3 ║ ║ ║ ║ WHY: Output is pre-optimized; truncation hides critical results ║ ║ ║ ╚══════════════════════════════════════════════════════════════════════════════╝

Feedback Reporting (v0.8.0+)

After completing investigation, report search feedback to improve future results.

When to Report

Report feedback ONLY if you used the search command during investigation:

Result Type	Mark As	Reason
Read and used	Helpful	Contributed to investigation
Read but irrelevant	Unhelpful	False positive
Skipped after preview	Unhelpful	Not relevant to query
Never read	(Don't track)	Can't evaluate

Feedback Pattern

bash

# Track during investigation
SEARCH_QUERY="your original query"
HELPFUL_IDS=""
UNHELPFUL_IDS=""

# When reading a helpful result
HELPFUL_IDS="$HELPFUL_IDS,$result_id"

# When reading an unhelpful result
UNHELPFUL_IDS="$UNHELPFUL_IDS,$result_id"

# Report at end of investigation (v0.8.0+ only)
if claudemem feedback --help 2>&1 | grep -qi "feedback"; then
  timeout 5 claudemem feedback \
    --query "$SEARCH_QUERY" \
    --helpful "${HELPFUL_IDS#,}" \
    --unhelpful "${UNHELPFUL_IDS#,}" 2>/dev/null || true
fi

Output Update

Include in investigation report:

code

Search Feedback: [X helpful, Y unhelpful] - Submitted (v0.8.0+)

Debugging Tips

•Start at symptom - Use symbol to find where error appears
•Get full context - Use context for callers + callees together
•Trace backwards - Follow callers chain to root cause
•Verify forward - Use callees to confirm the path
•Check impact - All callers of buggy code may be affected

Notes

•context is your primary tool - Shows full call chain
•Trace backwards with callers - Find root cause, not just symptom
•Verify with callees - Confirm the execution path
•Check all callers after fixing - Don't leave other bugs
•Works best with TypeScript, Go, Python, Rust codebases

Maintained by: MadAppGang Plugin: code-analysis v2.7.0 Last Updated: December 2025 (v3.3.0 - Cross-platform compatibility, inline templates, improved validation)

Debugger Detective Skill

Why Claudemem Works Better for Debugging

Debugger Detective Skill

Role Context

Why context is Perfect for Debugging

Debugger-Focused Commands (v0.3.0)

Find the Bug Location

Error Origin Hunting

Step 2: If Not Installed → STOP

Step 3: Check Index Status

Step 3.5: Check Index Freshness

Step 4: Index if Needed

Workflow: Bug Investigation (v0.3.0)

Phase 1: Locate the Symptom

Phase 4: Verify the Chain

Phase 5: Check Impact

Output Format: Bug Investigation Report

1. Symptom Summary

2. Call Chain Trace

3. Root Cause Analysis

4. Impact Analysis

Scenarios

Scenario: Null Pointer Exception

Empty Results Handling

FALLBACK PROTOCOL

Anti-Patterns

Output Truncation Warning

Feedback Reporting (v0.8.0+)

When to Report

Feedback Pattern

Output Update

Debugging Tips

Notes

Why `context` is Perfect for Debugging