This is more of a note to self for the next installation of Magento. On installing Magento on Nitrous.io, after file permissions are set, the error message “The mcrypt extension is missing. Please check your PHP configuration.” will be displayed.
To resolve this, go to the Nitrous command line and enter:
sudo php5enmod mcrypt
sudo service apache2 restart
This will then allow the system to proceed to the next step.