php-makephar/src/bootstrap.php

<?php

$loaders = [
    __DIR__."/../vendor/autoload.php",
    __DIR__."/../../../autoload.php",
];
foreach ($loaders as $loader) {
    if (file_exists($loader)) { require_once $loader; break; }
}

$app = new MakePhar\Application();
$app->run();