The use case :

• i got a doctrine embeddable (example: Identity)
• in forms, i want that my IdentityFormType to be used automatically

So :

• i make a Type Guesser which handle guessing for property of type Identity (as embeddable)

But :

• as all guessers are trieds by the ChainGuesser
• as the DoctrineOrmTypeGuesser threw an exception

So : that doesn't work

The Exception :
No mapping found for field 'identite' on class 'NSF\CoreBundle\Entity\Client'.
in vendor\doctrine\orm\lib\Doctrine\ORM\Mapping\MappingException.php (line 163)

My solution was to fix (in my way) into the DoctrineOrmTypeGuesser and to use my updated class with composer/autoload/file directive.