Symfony book problem

doctrine.yml

doctrine:

  orm:
        auto_generate_proxy_classes: true
        naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware
        auto_mapping: true
        mappings:
            App:
                is_bundle: false
                type: annotation
                dir: '%kernel.project_dir%/src/Entity'
                prefix: 'App\Entity'
                alias: App

DoctrineHelper.php

<?php
namespace Symfony\Bundle\MakerBundle\Doctrine;

final class DoctrineHelper
{

    /**
     * @return MappingDriver|LegacyMappingDriver|null
     *
     * @throws \Exception
     */
    public function getMappingDriverForClass(string $className)
    {
        /** @var EntityManagerInterface $em */
        $em = $this->getRegistry()->getManagerForClass($className);

        if (null === $em) {
            throw new \InvalidArgumentException(sprintf('Cannot find the entity manager for class "%s"', $className));
        }

        $metadataDriver = $em->getConfiguration()->getMetadataDriverImpl();

        /////////////////// patch
        // Doctrine bundle injects a proxy driver that hides target
        if ($metadataDriver instanceof \Doctrine\Bundle\DoctrineBundle\Mapping\MappingDriver) {
            $reflectionClass = new \ReflectionClass(get_class($metadataDriver));
            $property = $reflectionClass->getProperty('driver');
            $property->setAccessible(true);
            $metadataDriver = $property->getValue($metadataDriver);
        }
        ///////////////////

        if (!$this->isInstanceOf($metadataDriver, MappingDriverChain::class)) {
            return $metadataDriver;
        }

        foreach ($metadataDriver->getDrivers() as $namespace => $driver) {
            if (0 === strpos($className, $namespace)) {
                return $driver;
            }
        }

        return $metadataDriver->getDefaultDriver();
    }

gistfile1.txt

# https://symfony.com/doc/current/the-fast-track/en/8-doctrine.html#creating-entity-classes
# ---

% symfony new --version=stable myapp
% cd myapp
% symfony composer req logger orm
% symfony composer req maker --dev
% symfony console make:entity Acme
                                                                                                                        
 [ERROR] Only annotation mapping is supported by make:entity, but the <info>App\Entity\Acme</info> class uses a         
         different format. If you would like this command to generate the properties & getter/setter methods, add your  
         mapping configuration, and then re-run this command with the <info>--regenerate</info> flag.                   
                                                                                                                        

exit status 1

% php -v
PHP 8.0.3 (cli) (built: Mar  4 2021 20:42:56) ( NTS )
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