debugging

name	debugging
description	Debugging techniques for Python, JavaScript, and distributed systems. Activate for troubleshooting, error analysis, log investigation, and performance debugging.
allowed-tools	["Bash","Read","Write","Edit","Glob","Grep"]

Debugging Skill

Provides comprehensive debugging capabilities for the Golden Armada AI Agent Fleet Platform.

When to Use This Skill

Activate this skill when working with:

• Error troubleshooting
• Log analysis
• Performance debugging
• Distributed system debugging
• Memory and resource issues

Python Debugging

pdb Debugger

```python

Insert breakpoint

import pdb; pdb.set_trace()

Python 3.7+

breakpoint()

Common pdb commands

n(ext) - Execute next line

s(tep) - Step into function

c(ontinue) - Continue execution

p expr - Print expression

pp expr - Pretty print

l(ist) - Show source code

w(here) - Show stack trace

q(uit) - Quit debugger

```

Logging

```python import logging

logging.basicConfig( level=logging.DEBUG, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', handlers=[ logging.FileHandler('debug.log'), logging.StreamHandler() ] )

logger = logging.getLogger(name)

logger.debug("Debug message") logger.info("Info message") logger.warning("Warning message") logger.error("Error message", exc_info=True) ```

Exception Handling

```python import traceback

try: result = risky_operation() except Exception as e: # Log full traceback logger.error(f"Operation failed: {e}") logger.error(traceback.format_exc())

# Or get traceback as string
tb = traceback.format_exception(type(e), e, e.__traceback__)
error_details = ''.join(tb)

```

JavaScript/Node.js Debugging

Console Methods

```javascript // Basic logging console.log('Basic log'); console.error('Error message'); console.warn('Warning');

// Object inspection console.dir(object, { depth: null }); console.table(array);

// Timing console.time('operation'); // ... code ... console.timeEnd('operation');

// Stack trace console.trace('Trace point');

// Grouping console.group('Group name'); console.log('Inside group'); console.groupEnd(); ```

Node.js Inspector

```bash

Start with inspector

node --inspect app.js node --inspect-brk app.js # Break on first line

Debug with Chrome DevTools

Open chrome://inspect

```

VS Code Debug Configuration

```json { "version": "0.2.0", "configurations": [ { "type": "node", "request": "launch", "name": "Debug Agent", "program": "${workspaceFolder}/src/index.js", "env": { "NODE_ENV": "development" } } ] } ```

Container Debugging

Docker

```bash

View logs

docker logs --tail=100 -f

Execute shell

docker exec -it /bin/sh

Inspect container

docker inspect

Resource usage

docker stats

Debug running container

docker run -it --rm
--network=container:
nicolaka/netshoot ```

Kubernetes

```bash

Pod logs

kubectl logs -n agents -f kubectl logs -n agents --previous # Previous crash

Execute in pod

kubectl exec -it -n agents -- /bin/sh

Debug with ephemeral container

kubectl debug -n agents -it --image=busybox

Port forward for local debugging

kubectl port-forward 8080:8080 -n agents

Events

kubectl get events -n agents --sort-by='.lastTimestamp'

Resource usage

kubectl top pods -n agents ```

Log Analysis

Pattern Matching

```bash

Search logs for errors

grep -i "error|exception|failed" app.log

Count occurrences

grep -c "ERROR" app.log

Context around matches

grep -B 5 -A 5 "OutOfMemory" app.log

Filter by time range

awk '/2024-01-15 10:00/,/2024-01-15 11:00/' app.log ```

JSON Logs

```bash

Parse JSON logs with jq

cat app.log | jq 'select(.level == "error")' cat app.log | jq 'select(.timestamp > "2024-01-15T10:00:00")'

Extract specific fields

cat app.log | jq -r '[.timestamp, .level, .message] | @tsv' ```

Performance Debugging

Python Profiling

```python

cProfile

import cProfile cProfile.run('main()', 'output.prof')

Line profiler

@profile def slow_function(): pass

Memory profiler

from memory_profiler import profile

@profile def memory_heavy(): pass ```

Network Debugging

```bash

Check connectivity

ping telnet nc -zv

DNS resolution

nslookup dig

HTTP debugging

curl -v http://localhost:8080/health curl -X POST -d '{"test": true}' -H "Content-Type: application/json" http://localhost:8080/api ```

Common Debug Checklist

1. Check Logs: Application, system, container logs
2. Verify Configuration: Environment variables, config files
3. Test Connectivity: Network, database, external services
4. Check Resources: CPU, memory, disk space
5. Review Recent Changes: Git log, deployment history
6. Reproduce Locally: Same environment, same data
7. Binary Search: Isolate the problem scope