I use this functions to help me debugging wordpress

wordpress debug functions

/* debug functions */

error_reporting(E_ALL);
ini_set("display_errors", 1);


function debug_wp_rewrite_rules() {
	global $wp_rewrite;
	echo '<div>';
	if (!empty($wp_rewrite->rules)) {
		echo '<h5>Rewrite Rules</h5>';
		echo '<table><thead><tr>';
		echo '<td>Rule</td><td>Rewrite</td>';
		echo '</tr></thead><tbody>';
		foreach ($wp_rewrite->rules as $name => $value) {
			echo '<tr><td>'.$name.'</td><td>'.$value.'</td></tr>';
		}
		echo '</tbody></table>';
	} else {
		echo 'No rules defined.';
	}
	echo '</div>';
}
function debug_wp_page_request() {
	global $wp, $template;
	echo '<!-- Request: ';
	echo empty($wp->request) ? "None" : esc_html($wp->request);
	echo ' -->'."\r\n";
	echo '<!-- Matched Rewrite Rule: ';
	echo empty($wp->matched_rule) ? None : esc_html($wp->matched_rule);
	echo ' -->'."\r\n";
	echo '<!-- Matched Rewrite Query: ';
	echo empty($wp->matched_query) ? "None" : esc_html($wp->matched_query);
	echo ' -->'."\r\n";
	echo '<!-- Loaded Template: ';
	echo basename($template);
	echo ' -->'."\r\n";
}