Cannot autowire service: Argument references class but no such service exists

Question

I'm upgrading a project from Symfony 3 to Symfony 4 (https://github.com/symfony/symfony/blob/master/UPGRADE-4.0.md) and I have many repository/services like this:

namespace App\Entity;

use App\Entity\Activation;
use Doctrine\ORM\EntityRepository;
use Predis\Client;

class ActivationRepository extends EntityRepository
{
    // ...
}

And when I try to run the project in the browser like this:

http://localhost:8000/login

I get this error:

(1/1) RuntimeException
Cannot autowire service "App\Entity\ActivationRepository": 
argument "$class" of method 
"Doctrine\ORM\EntityRepository::__construct()" 
references class "Doctrine\ORM\Mapping\ClassMetadata" 
but no such service exists.

Does this mean you have to create a service for "Doctrine\ORM\Mapping\ClassMetadata" in your services.yaml file?

Thanks to autowiring my new services.yaml file is fairly small compared to the old one, which had 2000+ lines. The new services.yaml just has several of these (so far):

App\:
    resource: '../src/*'

# Controllers
App\Controller\:
    resource: '../src/Controller'
    autowire: true
    public: true
    tags: ['controller.service_arguments']

# Models
App\Model\:
    resource: '../src/Model/'
    autowire: true
    public: true

// etc

Question: Do you really need to add service definitions to services.yaml for third party vendor classes? And if so, can I get an example of how to do that please? Any advice from anyone who has already upgraded from Symfony 3 to Symfony 4 would be great.

PHP 7.2.0-2+ubuntu16.04.1+deb.sury.org+2 (cli) (built: Dec 7 2017 20:14:31) ( NTS ) Linux Mint 18, Apache2 Ubuntu.

EDIT / FYI:

This is the "Doctrine\ORM\EntityRepository::__construct()" which the ActivationRepository extends:

/**
     * Initializes a new <tt>EntityRepository</tt>.
     *
     * @param EntityManager         $em    The EntityManager to use.
     * @param Mapping\ClassMetadata $class The class descriptor.
     */
    public function __construct(EntityManagerInterface $em, Mapping\ClassMetadata $class)
    {
        $this->_entityName = $class->name;
        $this->_em         = $em;
        $this->_class      = $class;
    }

which is located here:

/vendor/doctrine/orm/lib/Doctrine/ORM/EntityRepository.php

Answer 1

Do you really need to add service definitions to services.yaml for third party vendor classes?

No, don't do that. My personal suggestion is: don't extend EntityRepository. Ever. You don't want your repository's interface to have method like createQuery or flush. At least, you don't want that if you consider a repository just like a collection of objects. If you extend EntityRepository you will have a leaky abstraction.

Instead you can inject the EntityManager inside your repository, and that's it:

use App\Entity\Activation;
use App\Repository\ActivationRepository;
use Doctrine\ORM\EntityManagerInterface;

final class DoctrineActivationRepository implements ActivationRepository
{
    private $entityManager;
    private $repository;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->entityManager = $entityManager;
        $this->repository = $this->entityManager->getRepository(Activation::class);
    }

    public function store(Activation $activation): void
    {
        $this->entityManager->persist($activation);
        $this->entityManager->flush();
    }

    public function get($id): ?Activation
    {
        return $this->repository->find($id);
    }

    // other methods, that you defined in your repository's interface.
}

No other steps are required.

Answer 2

My issue was a wrong namespace. File real position was App\Infrastructure\MySQL\Rubric\Specification But namespace was set to App\Infrastructure\Rubric\Specification

Result "[blah blah] but no such service exists".