You can enable debugging during application instantiation with this setting:
<?php
$app = new \Slim\Slim(array(
'debug' => true
));
You may also enable debugging during runtime with the Slim application’s config() instance method:
<?php
$app = new \Slim\Slim();
//Enable debugging (on by default)
$app->config('debug', true);
//Disable debugging
$app->config('debug', false);
If debugging is enabled and an exception or error occurs, a diagnostic screen will appear with the error description, the affected file, the file line number, and a stack trace. If debugging is disabled, the custom Error handler will be invoked instead.