Looks like there was a circular dependency in ConnectionAdapter.php
Updated to be:
protected static function getSqlSrvDsn(array $config)
{
// First we will create the basic DSN setup as well as the port if it is in
// in the configuration options. This will give us the basic DSN we will
// need to establish the PDO connections and return them back for use.
if (in_array(‘dblib’, static::getAvailableDrivers())) {
return static::getDblibDsn($config);
} else {
return static::getNonDblibDsn($config);
}
}