Escape route from legacy index.php

index.php

<?php
// Composer autoloader
$loader = require __DIR__ . '/../vendor/autoload.php';

// Legacy config which includes legacy autoloader stuff
require_once __DIR__ . '/../html/config.php';

// Legacy bootstrapping code wrapped in a class implementing HttpKernelInterface to make it stackable
require __DIR__ . '/../html/Bootstrap.php';

use Acme\AppKernel;
use Doctrine\Common\Annotations\AnnotationRegistry;

// Load up annotations
AnnotationRegistry::registerLoader(array($loader, 'loadClass'));

// Load up AppKernel, $symfony_env is set in the legacy config file
$debug = $symfony_env !== 'prod';
$kernel = new AppKernel($symfony_env, $debug);
$kernel->loadClassCache();

// Create a Stack Builder
$stack = new Stack\Builder();

// Stack the Symfony Application using a pre-made SymfonyMiddleware
$stack->push('Mouf\StackPhp\SymfonyMiddleware', $kernel);

// Run the stack with the legacy app lazy loaded(so it doesn't get bootstrapped)
Stack\run(
    $stack->resolve(
        Stack\lazy(function() {
            return new Bootstrap();
        })
    )
);