I had an entity class in Aib\\PlatformBundle\\Entity\\User.php
I had no problems trying to create its form class through
php app/ console doc
big thx to Mark Fu and mogoman
I knew it had to be somewhere in the config.yml... and being able to test it against the
app/console doctrine:mapping:info
really helped!
In fact, this command just simply stops at an error... no feedback, but when everything is fine you should be able to see all your entities listed.