Enable logging
Just add a directory named log to you application root folder.
$ cd my_app
$ mkdir log
However this tip does not seem to work with newer version of Mojolicious, so you might have to add the following to your application.
Mojolicious::Lite
use Mojo::Log;
my $log = Mojo::Log->new( path => 'log/development.log', level => 'debug' );
app->log($log);
Mojolicious Application
use Mojo::Log;
# Log to STDERR
my $log = Mojo::Log->new;
# Customize log file location and minimum log level
my $log = Mojo::Log->new(path => '/var/log/mojo.log', level => 'warn');
Above example lifted from Mojo::Log