Debugging in moodle config.php

To turn on debugging in moodle config.php, you need to add code

@error_reporting(1023);
@ini_set('display_errors', '1');
$CFG->debug = 38911;
$CFG->debugdisplay = true;

To show only to your user account
$CFG->debugusers = '2';   (replace 2 with your moodle userid)

$CFG->debug = X

Where X can be:
0 - none
5 - minimal
15 - normal
6143 - all
38911 - developer

And to show it

$CFG->debugdisplay (1, or 0)

controls whether debug messages are included in the HTML output. 0 means it goes to Apache's error log.