Symfony 2 - 共享供应商目录不适用于资产

I make symlinks to vendor directory located outside application directories, and everything works good, but no assetic bundle.

www
 |- project1
 |- project2
 |- projectx
 |- vendor

When I add in config.yml:

assetic:
    assets:
        main_css:
            inputs:
                - @AppBundle/Foundation/stylesheets/app.css

It doesn't work: "Unable to find file "@AppBundle/Foundation/stylesheets/app.css"."

But if changed to:

assetic:
    assets:
        main_css:
            inputs:
                - %kernel.root_dir%/../src/AppBundle/Foundation/stylesheets/app.css

It works again. The same happens with twig templates:

{% stylesheets '@AppBundle/Foundation/stylesheets/app.css' %}
    <link rel="stylesheet" href="{{ asset_url }}" />
{% endstylesheets %}

It doesn't work.

Even if I'm not using symbolic links, but only changing loader path in app/autoloader.php, it doesn't work.

What can be done to make it work?