错误[Assetic \ Exception \ FilterException] Symfony Assetic与SASS Compass

Question

我正在尝试配置symfony资产管理器来编译我的scss文件并重写路径但是我收到以下错误：

  [Assetic\Exception\FilterException]
  An error occurred while running:
  '/usr/bin/ruby' '/usr/local/bin/sass' '--load-path' '/var/www/karta-otdyha/src/App/WebBundle/Resources/assets/scss' '--scss' '--style' 'compressed' '--cache-locati
  on' '/tmp' '--compass' '/tmp/assetic_sass463p4z'
  Error Output:
  TypeError: superclass mismatch for class Literal
    Use --trace for backtrace.
  Input:
...
  /*# sourceMappingURL=assetic_compassmpX1yk.css.map */

我的config.yml

assetic:
    debug: %kernel.debug%
    use_controller: true
    bundles:        [ AppWebBundle ]
    ruby:           /usr/bin/ruby
    sass:           /usr/local/bin/sass
    filters:
        cssrewrite: ~
        scss:
            style: 'compressed'
            compass: true
            apply_to: "\.scss$"
        compass:
           images_dir: %kernel.root_dir%/../src/App/WebBundle/Resources/assets/images
           http_path: /bundles/appweb
           generated_images_path: %kernel.root_dir%/../src/App/WebBundle/Resources/public/images
           bin: /usr/local/bin/compass

我正在使用Ubuntu 14.04和PHP 5.5.9，有谁知道我该如何修复它？