Doctrine Single Table Inheritance working with YAML service configuration but not XML

PriceQuoteRequest.php

<?php

namespace Sps\Bundle\PriceQuoteBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * PriceQuoteRequest
 *
 * @ORM\Entity(repositoryClass="Sps\PriceQuote\Infrastructure\Persistence\Doctrine\DoctrinePriceQuoteRepository")
 * @ORM\InheritanceType("SINGLE_TABLE"))
 * @ORM\DiscriminatorColumn(name="type", type="integer")
 * @ORM\DiscriminatorMap({
 *     "1" = "DormerPriceQuote",
 *     "2" = "BayWindowPriceQuote"
 * }) 
 */
abstract class PriceQuoteRequest
    extends AbstractPriceQuote
    implements PriceQuote
{}

services.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>

        <service id="sps.price_quote.repository.dormer"
                 class="Doctrine\ORM\EntityRepository">
            <factory class="%doctrine.orm.entity_manager.class%" method="getRepository"/>
            <argument>Plusquam\Bundle\PriceQuoteBundle\Entity\DormerPriceQuote</argument>
        </service>

    </services>
</container>

services.yml

services:
    sps.price_quote.repository.dormer:
        class: Doctrine\ORM\EntityRepository
        factory: [ "%doctrine.orm.entity_manager.class%", getRepository ]
        arguments:
            - Sps\Bundle\PriceQuoteBundle\Entity\PriceQuoteRequest
        public: false
        

Using the YAML configuration works just fine. But XML throws:

Using $this when not in object context

Any idea?

Came from:

• https://twitter.com/webdevilopers/status/805003557665652736

Maybe @craigh has an idea. He seemed to have a similar problem here:

• http://php-and-symfony.matthiasnoback.nl/2014/05/inject-a-repository-instead-of-an-entity-manager/#comment-2292556713