当我运行 rake assets:precompile RAILS_ENV=production 时，不包括从 gem 中使用的资产，我的网站显示这些资产没有找到很多 404。
pnotify.core-4a29894be02cb147dd67c1f609148e95.css:1 Failed to load resource: the server responded with a status of 404 (Not Found)
pnotify.buttons-19d9aeb87c03cfef956313439afad682.css:1 Failed to load resource: the server responded with a status of 404 (Not Found)
pnotify.history-d339b3266d96cddfa55c4f0478f9d0ea.css:1 Failed to load resource: the server responded with a status of 404 (Not Found)
关于生产Rails.application.config.assets.paths显示：
=> ["/vagrant/local/app/assets/fonts",
"/vagrant/local/app/assets/images",
"/vagrant/local/app/assets/javascripts",
"/vagrant/local/app/assets/stylesheets",
"/vagrant/local/vendor/assets/javascripts",
"/vagrant/local/vendor/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/material_icons-2.2.1/app/assets/fonts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/material_icons-2.2.1/app/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/chosen-rails-1.5.2/vendor/assets/images",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/chosen-rails-1.5.2/vendor/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/chosen-rails-1.5.2/vendor/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/cocoon-1.2.6/app/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-minicolors-rails-2.1.4.0/vendor/assets/images",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-minicolors-rails-2.1.4.0/vendor/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-minicolors-rails-2.1.4.0/vendor/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/pnotify-rails-2.0.1.1/vendor/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/pnotify-rails-2.0.1.1/vendor/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/tinymce-rails-4.1.0/app/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/tinymce-rails-4.1.0/app/assets/source",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/tinymce-rails-4.1.0/vendor/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-ui-rails-4.1.2/app/assets/images",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-ui-rails-4.1.2/app/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-ui-rails-4.1.2/app/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/activeadmin-0.6.0/app/assets/images",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/activeadmin-0.6.0/app/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/activeadmin-0.6.0/app/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/formtastic-2.2.1/app/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/bourbon-4.0.2/app/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/jquery-rails-3.1.1/vendor/assets/javascripts",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/font-awesome-sass-5.3.1/assets/stylesheets",
"/home/vagrant/.rvm/gems/ruby-1.9.3-p385/gems/font-awesome-sass-5.3.1/assets/fonts"]
欢迎任何帮助！
问题是config.assets.debug选项，它在生产服务器上true，并且 CDN 中没有文件。
就这么简单。