PDO is not required and there is a workaround for the problem situation where you have PHP 5.1+ but do not have the PDO_mysql driver available (which is why it is failing here). But you must force xPDO to use an emulated version of PDO (included in xPDO) by setting a constant in each of your index.php entry points (i.e. /index.php, /manager/index.php, /connectors/index.php). Here is the code you’ll uncomment and copy to each one; it’s included in the index.php.
<?php
//[OPTIONAL]: for forcing emulated PDO when required native PDO drivers are not available
define('XPDO_MODE', 2);
?>
I’m looking for a way to detect and automate setting this mode.
That said, everyone with PHP 5.1 and MySQL in the same environment should absolutely have the mysql PDO driver in their configuration, or request that it be added.