Debug
Systematically debug app issues by examining logs, database state, and git history
What You Can Do
You can systematically investigate application failures by examining logs, querying database state, and reviewing git history to identify root causes. This skill helps you understand the current state of your system without making changes, providing the contextual foundation needed to solve bugs efficiently during manual testing or implementation work.
Features
automatically locate and parse application logs from common directories to identify error patterns and stack traces
query SQLite databases and check database configuration to understand data consistency and state issues
review current branch, recent commits, and uncommitted changes to correlate code changes with observed problems
verify running processes and listening ports to diagnose connectivity and service availability issues
analyze plan/ticket files to align debugging investigation with intended test cases or implementation goals
cross-reference logs, database state, and git changes to identify patterns and root causes
gather all diagnostic information without modifying files or system state
Example Output
Example 1: Database Query Issue
I found the issue! Looking at the logs, there's a SQL syntax error at 2024-01-15 14:32:18. The recent commit (abc123) changed the query structure. Checking the database state, the `users` table is missing the `status` column that the new query expects. The migration appears to be uncommitted in your working directory.
Example 2: Service Connectivity Problem
The service logs show connection refused errors. Running `lsof -i :5432`, the database isn't listening on port 5432. Git history shows the database configuration changed 3 commits ago from localhost to 127.0.0.1. The process list shows the database service isn't running—likely crashed during startup due to the configuration change.
What's Included
- SKILL.md: Core debugging instruction set with investigation process
- Debugging checklist: Systematic steps for logs, database, and git examination
- Common log locations reference: Default paths for application logs across systems
- SQL query templates: Pre-built queries for common database state investigations
- Git command reference: Quick commands for branch, commit, and change analysis
Who It's For
- Backend engineers — debugging application failures and service issues during development
- QA/test engineers — investigating test failures and understanding failure root causes
- Full-stack developers — correlating frontend errors with backend state and logs
- DevOps engineers — diagnosing service and deployment issues
- Implementation specialists — troubleshooting issues during feature rollout or integration work
Best For
- Failure investigation — understanding why tests or features are failing
- Production troubleshooting — diagnosing live issues without making changes
- State verification — checking database consistency and service status
- Change correlation — identifying which code changes caused problems
- Debugging session bootstrap — gathering complete context before implementing fixes
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