SonataUserBundle + FOSUserBundle Annotation Issue Doctrine Primary Key Error

Using Symfony 4.1, Sonata User Bundle 4.x, and FOSUserBundle 2.1.2.

I am trying to override the table names for the User and Group tables. I therefore added annotations to the auto generated user and group classes:

use Sonata\UserBundle\Entity\BaseGroup as BaseGroup;
use Doctrine\ORM\Mapping as ORM;

/**
 * This file has been generated by the SonataEasyExtendsBundle.
 * @ORM\Entity()
 * @ORM\Table(name="aegis_group")
 * @link https://sonata-project.org/easy-extends 
 * References:
 * @link http://www.doctrine-project.org/projects/orm/2.0/docs/reference/working-with-objects/en
 */
class Group extends BaseGroup
{
    /**     
     * @ORM\Id      
     * @var int $id
     */
    protected $id;

   /**
     * Get id.
     *
     * @return int $id
     */
    public function getId()
    {
        return $this->id;
    }    
}

I then modified doctrine.yaml to factor in these annotations:

        mappings:                    
                App:
                    is_bundle: false
                    type: annotation
                    dir: '%kernel.project_dir%/src/Entity'
                    prefix: 'App\Entity'
                    alias: App
                FOSUserBundle: ~                                          
                ApplicationSonataUserBundle: 
                    type: annotation
                SonataUserBundle: ~   

However, when I run migrations, doctrine gives me an error:

In MappingException.php line 46:

No identifier/primary key specified for Entity "App\Application\Sonata\User Bundle\Entity\Group" sub class of "Sonata\UserBundle\Entity\BaseGroup". Every Entity must have an identifier/primary key.

How to fix this issue, so that I can use my own custom table names ? All I want to do is to change the database table names, this should not be this involved.

Well, turns out an XML orm file is generated by the SonataEasyExtendsBundle, in directory Application\Sonata\UserBundle\Resources\config\doctrine folder. One should modify this file (User.orm.xml) to make changes to the table config.

<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                  xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping
                  http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

    <entity name="App\Application\Sonata\UserBundle\Entity\User" table="aegis_user">

        <id name="id" column="id" type="integer">
            <generator strategy="AUTO" />
        </id>

    </entity>

</doctrine-mapping>