See : http://php.net/manual/en/mysqli.construct.php

Specifying the socket parameter will not explicitly determine the type of connection to be used when connecting to the MySQL server. How the connection is made to the MySQL database is determined by the host parameter.

This means that in ezmysqlidb.php, if server = 'localhost', the connection is done through socket even if $socketPath = false, ending in an error in some case.