Error Logs not showing up when debugging?

[DrByte]

If there are no PHP-level errors, then the log file won't be created. Same with STRICT_ERROR_REPORTING.
If the file/folder isn't writable, then the logs can't be created.
The zc_xxxxxx.sql files are query caching. Their presence suggests that the folder is properly writable.

[deeve]

Many thanks for taking the time to reply, Dr Byte.
Do you have any idea why these myDEBUG-xxxxxx files were showing up in the Server/Version Info page within the PHP Core 'error_log' section? When I turn the php script off it then shows them as 'error_log'.

Apologies in advance for not grasping this myself.

[DrByte]

The log filename will appear in the phpinfo output as the 'error_log' filename specified for the current operating session. But, as I said before, the file will not actually be created if there are no errors generated to put into it.