In my Symfony 6.4 project, I’m trying to declare an abstract service in services.yaml by doing the following :

services:
  _defaults:
    autowire: true
    autoconfigure: true

  AppAdminFormHostingFormAbstract:
    arguments:
      $authorizationChecker: '@security.authorization_checker'
      $tokenStorage: '@security.token_storage'
      $phpHandlers: '%php_handlers%'
      $nodeJsHandlers: '%nodeJs_handlers%'
    abstract:  true
...

The HostingFormAbstract class is extending AbstractType from symfony/form package :

namespace AppAdminForm;

use SymfonyComponentFormAbstractType;
use SymfonyComponentFormExtensionCoreTypeChoiceType;
use SymfonyComponentFormExtensionCoreTypeCollectionType;
use SymfonyComponentFormExtensionCoreTypeTextareaType;
use SymfonyComponentFormExtensionCoreTypeTextType;
use SymfonyComponentFormExtensionCoreTypeCheckboxType;
use SymfonyComponentFormFormBuilderInterface;
use SymfonyComponentSecurityCoreAuthenticationTokenStorageTokenStorageInterface;
use SymfonyComponentSecurityCoreAuthorizationAuthorizationCheckerInterface;
use SymfonyComponentSecurityCoreUserUserInterface;
use SymfonyComponentValidatorConstraintsNotBlank;

abstract class HostingFormAbstract extends AbstractType
{
    
    private TokenStorageInterface $tokenStorage;
    private AuthorizationCheckerInterface $authorizationChecker;
    private array $phpHandlers;
    private array $nodeJsHandlers;

    public function __construct(TokenStorageInterface $tokenStorage, AuthorizationCheckerInterface $authorizationChecker, array $phpHandlers, array $nodeJsHandlers)
    {
        $this->tokenStorage = $tokenStorage;
        $this->authorizationChecker = $authorizationChecker;
        $this->phpHandlers = $phpHandlers;
        $this->nodeJsHandlers = $nodeJsHandlers;
    }
...

And with that, I get the following error while going on my symfony app :

The service "AppAdminFormHostingFormAbstract" tagged "form.type" must not be abstract.

For more context, I’m rewriting a Symfony 3.4 app into a new Symfony 6.4 app.

It was working fine on 3.4, but now it seems that in services.yaml, you can’t declare an abstract service/class extending the AbstractType class.

I tried to add a custom tag in the yaml for this service, but it didn’t change anything.

I didn’t find any workaround on Symfony documentation, and it seems odd to me that you can’t do that. Maybe I missed something.

If anyone as an idea on how to do this…

Thanks !