Investigate Logs

Investigate Logs

Automatically investigate PhotoClove logs to diagnose issues and errors.

When This Skill is Invoked

Claude automatically uses this skill when:

• User reports an error or bug
• Functionality isn't working as expected
• Need to trace what happened during an operation
• Debugging why something failed
• User says "check the logs" or similar

Log Locations

Frontend Logs

Location: LogViewer component (accessible via Ctrl+Shift+L)

• Stored in memory via LoggerService.js
• Structured format: [LEVEL] Component:event_name - Message | data: {...}
• Can be filtered by level, component, and searched

Daily Log Files (UTC dates):

~/.local/share/photoclove/logs/photoclove-frontend-YYYY-MM-DD.log

Example: photoclove-frontend-2025-12-23.log (December 23, 2025 UTC)

Backend Logs

Location: Daily log files in the logs directory (UTC dates)

~/.local/share/photoclove/logs/photoclove-YYYY-MM-DD.log

Example: photoclove-2025-12-23.log (December 23, 2025 UTC)

Format: Rust log:: macros with structured key=value pairs

[TIMESTAMP] [LEVEL] target: "component", "event; key1=value1; key2=value2"

Important: Log file names use UTC dates, not local timezone dates.

Investigation Process

1. Identify the issue:

   • What operation failed?
   • What was the user doing?
   • When did it happen?

2. Check most recent logs (log files use UTC dates):

   # Frontend logs (today UTC)
   tail -100 ~/.local/share/photoclove/logs/photoclove-frontend-$(date -u +%Y-%m-%d).log
   
   # Backend logs (today UTC)
   tail -100 ~/.local/share/photoclove/logs/photoclove-$(date -u +%Y-%m-%d).log
   
   # Or simply check the latest files
   tail -100 ~/.local/share/photoclove/logs/photoclove-frontend-*.log | tail -100
   tail -100 ~/.local/share/photoclove/logs/photoclove-*.log | grep -v frontend | tail -100
   

3. Search for errors:

   # Find errors in frontend logs
   grep -i "error" ~/.local/share/photoclove/logs/photoclove-frontend-*.log | tail -20
   
   # Find errors in backend logs
   grep -i "error" ~/.local/share/photoclove/logs/photoclove-2*.log | tail -20
   

4. Trace operation flow:

   • Look for correlation_id in logs to trace a request through frontend and backend
   • Follow the sequence of events leading to the error
   • Check what data was passed at each step

5. Identify root cause:

   • What was the first error in the chain?
   • What state was the application in?
   • What data caused the issue?

Common Error Patterns

Frontend Errors

• ReferenceError: Undefined variable or function
• TypeError: Wrong type or null/undefined access
• State errors: Incorrect state updates or missing state

Backend Errors

• Database errors: SQL errors, table not found, constraint violations
• File system errors: Permission denied, file not found
• Tauri command errors: Command not found, invalid parameters

Integration Errors

• 500 Internal Server Error: Backend error, check backend logs
• No response: Command timeout or backend crash
• Data mismatch: Frontend and backend data format mismatch

Log Analysis Tips

1. Start from the error and work backwards
2. Look for correlation_id to trace requests
3. Check timestamps to understand timing
4. Pay attention to data values in structured logs
5. Compare with successful operations

Reporting Findings

After investigation, provide:

• Root cause: What actually caused the error
• Error location: File and line number if available
• Data context: What data triggered the issue
• Suggested fix: How to resolve the problem
• Related logs: Key log entries showing the issue

Integration with PhotoClove

• Frontend logs use LoggerService.js for structured logging
• Backend logs use Rust log:: macros
• All operations should have correlation IDs for tracing
• LogViewer provides UI for browsing logs interactively