EngineInterface is deprecated in Symfony 4.3, and they will only work with Twig

[Richard87]

TwigEngine is deprecated in Symfony 4.3

/**
 * This engine knows how to render Twig templates.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 *
 * @deprecated since version 4.3, to be removed in 5.0; use Twig instead.
 */
class TwigEngine implements EngineInterface, StreamingEngineInterface
{

Since APYBreadcrumbTrailBundle uses Twig anyway:

        <service id="apy_breadcrumb_trail.twig.extension" class="%apy_breadcrumb_trail.twig.extension.class%">
            <argument type="service" id="apy_breadcrumb_trail" />
            <argument type="service" id="twig" />
            <tag name="twig.extension" />
        </service>

(by the name twig.extension, it should just take the twig service, wich solves the problem).

    /**
     * BreadcrumbTrailExtension constructor.
     * @param Trail $trail
     * @param Environment $templating
     */
    public function __construct(Trail $trail, Twig\Environment $templating)
    {
        $this->trail = $trail;
        $this->templating = $templating;
    }