As per http://www.php.net/manual/en/tokens.php - the T_AMPERSAND token does not exist. I'm not sure what was the intent, but the entity generator fails on the following code:
Due to the way notices are handled in Symfony, this basically stops the execution of the generator entirely. Not so great.
Commenting out the offending line makes it work fine though, so I think it's just choking while expecting a function that takes args by reference or something.