Symfony 2 / Propel：找不到类'Phing'，自动加载？

I've a weird problem with propel. My configuration in config.yml:

propel:

    dbal:
        driver:     %database_driver%
        user:       %database_user%
        password:   %database_password%
        dsn:        %database_driver%:host=%database_host%;dbname=%database_name%;charset=UTF8
        path:       %kernel.root_dir%/../vendor/propel
        phing_path: %kernel.root_dir%/../vendor/phing

I created my database with that command: php app/console propel:database:create and it worked very well but when I'm trying to create my first table with php app/console propel:model:build i've a fatal error telling: PHP Fatal error: Class 'Phing' not found.

I verified in the folder, everything is there. I guess that is an autoloading problem but I've followed the documentation at http://www.propelorm.org/cookbook/symfony2/working-with-symfony2.html and http://symfony.com/doc/master/book/propel.html

Any idea? Thanks a lot!

Which dependencies management system do you use?

This is an autoloading issue, and you should add the following definition:

$loader->registerPrefixes(array(
    ...

    'Phing' => __DIR__.'/../path/to/phing/classes/phing',
));

where path/to/phing is the path where you installed Phing.