debugger-detective
⚡ PRIMARY TOOL for: 'why is X broken', 'find bug source', 'root cause analysis', 'trace error', 'debug issue', 'find where X fails'. Uses claudemem v0.3.0 AST with context command for call chain analysis. GREP/FIND/GLOB ARE FORBIDDEN.
$ 설치
git clone https://github.com/MadAppGang/claude-code /tmp/claude-code && cp -r /tmp/claude-code/plugins/code-analysis/skills/debugger-detective ~/.claude/skills/claude-code// tip: Run this command in your terminal to install the skill
name: debugger-detective description: "⚡ PRIMARY TOOL for: 'why is X broken', 'find bug source', 'root cause analysis', 'trace error', 'debug issue', 'find where X fails'. Uses claudemem v0.3.0 AST with context command for call chain analysis. GREP/FIND/GLOB ARE FORBIDDEN." allowed-tools: Bash, Task, Read, AskUserQuestion
⛔⛔⛔ CRITICAL: AST STRUCTURAL ANALYSIS ONLY ⛔⛔⛔
╔══════════════════════════════════════════════════════════════════════════════╗
║ ║
║ 🧠 THIS SKILL USES claudemem v0.3.0 AST ANALYSIS EXCLUSIVELY ║
║ ║
║ ❌ GREP IS FORBIDDEN ║
║ ❌ FIND IS FORBIDDEN ║
║ ❌ GLOB IS FORBIDDEN ║
║ ║
║ ✅ claudemem --agent context <name> FOR FULL CALL CHAIN ║
║ ✅ claudemem --agent callers <name> TO TRACE BACK TO SOURCE ║
║ ✅ claudemem --agent callees <name> TO TRACE FORWARD ║
║ ║
║ ⭐ v0.3.0: context shows full call chain for root cause analysis ║
║ ║
╚══════════════════════════════════════════════════════════════════════════════╝
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
# 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
# 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
# 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:
# 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
claudemem index
Workflow: Bug Investigation (v0.3.0)
Phase 1: Locate the Symptom
# 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
# Once you suspect a root cause, verify the path
claudemem --agent callees suspectedRoot
# Does it lead to the symptom?
Phase 5: Check Impact
# What else calls the buggy code?
claudemem --agent callers buggyFunction
# These are all potentially affected
Output Format: Bug Investigation Report
1. Symptom Summary
┌─────────────────────────────────────────────────────────┐
│ 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
❌ 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
🔍 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
⚠️ 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
# 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
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
// 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
# 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:
Search Feedback: [X helpful, Y unhelpful] - Submitted (v0.8.0+)
Debugging Tips
- Start at symptom - Use
symbolto find where error appears - Get full context - Use
contextfor callers + callees together - Trace backwards - Follow
callerschain to root cause - Verify forward - Use
calleesto confirm the path - Check impact - All
callersof buggy code may be affected
Notes
contextis 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)
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