Error logging

If you have set WP_DEBUG and WP_DEBUG_LOG to true in your WordPress wp-config.php file but you are not seeing the debug messages in the debug log file, there could be a few reasons for this behavior. Here are some steps you can take to troubleshoot and resolve the issue:

1. Check File Permissions:
   Ensure that the directory where the debug log file is supposed to be written has the correct permissions that allow PHP to write to it. Typically, the file should be writable by the web server user (e.g., www-data on Apache).
2. Verify Debug Log Location:
   WordPress debug logs are usually written to wp-content/debug.log unless you have explicitly defined a different location using the WP_DEBUG_LOG constant. Double-check the location to ensure you are looking at the correct file.
3. Verify wp-config.php Changes:
   Double-check your wp-config.php file to ensure that the WP_DEBUG and WP_DEBUG_LOG constants are set correctly. Make sure there are no typos or syntax errors in the file.
4. Check Error Reporting Level:
   Ensure that your PHP error reporting level includes notices and warnings. If the errors you are trying to log are not severe enough, they may not appear in the debug log. You can set the error reporting level in your php.ini file or in your WordPress wp-config.php file using error_reporting(E_ALL);.
5. Check for Output Buffering:
   Output buffering can sometimes interfere with debug output. Make sure that there are no functions or settings in your code that are buffering output, which could prevent the debug messages from being written to the log file.
6. Test with Simple Debug Message:
   Instead of using error_log('hello');, try using error_log('hello', 0); or error_log('hello', 3, '/path/to/debug.log'); directly in your PHP code to see if any message gets logged. This can help isolate whether the issue is with the error_log function or with the debug settings.
7. Review Server Error Logs:
   Check your server’s error logs (e.g., Apache error log, PHP error log) for any relevant messages or errors that might indicate why the debug messages are not being logged as expected.

By following these steps and checking these common issues, you should be able to diagnose why your error_log messages are not appearing in the WordPress debug log file.