带有rails 4的bootstrap-sass会给出响应错误

我正在将rails 3.2.8应用程序（包含引导但不响应）升级到rails 4.0.1 .

我的Gemfile内容是

source 'https://rubygems.org'
ruby '2.0.0'
gem 'rails', '4.0.1'
gem 'haml'

#rails 4 doesnt support assets group. only test, dev n prod
gem 'sass'
gem 'sass-rails',    '~> 4.0.0'
gem 'bootstrap-sass'
gem 'coffee-rails'
gem "jquery-scrollto-rails"

# See https://github.com/sstephenson/execjs#readme for more supported runtimes
gem 'therubyracer'
gem 'uglifier'

group :production do
  gem 'dalli'
end

gem 'jquery-rails'
gem 'actionpack-page_caching' #use caches_pages in rails 4

application.js的内容是

//= require jquery
//= require jquery_ujs
//= require bootstrap
//= require_tree .

application.css.scss的内容和

@import "bootstrap";
@import "josh";

这是我第一次和萨斯一起 . 我的问题是

1）与sass相关的宝石是否正确指定或是否有任何不需要的宝石？

2）我的应用程序呈现正确（无响应），但如果我添加'@import“bootstrap-responsive”;'在css.scss文件中的import bootstrap下面，我得到错误

Sass::SyntaxError in Static#home
Showing /home/prasad/projects/website/app/views/layouts/application.html.haml where line #31 raised:

File to import not found or unreadable: bootstrap-responsive.
Load paths:
  /home/prasad/projects/website/app/assets/images
  /home/prasad/projects/website/app/assets/javascripts
  /home/prasad/projects/website/app/assets/stylesheets
  /home/prasad/projects/website/vendor/assets/javascripts
  /home/prasad/projects/website/vendor/assets/stylesheets
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/jquery-rails-3.0.4/vendor/assets/javascripts
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/jquery-scrollto-rails-1.4.3/vendor/assets/javascripts
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/coffee-rails-4.0.1/lib/assets/javascripts
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/bootstrap-sass-3.0.2.1/vendor/assets/fonts
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/bootstrap-sass-3.0.2.1/vendor/assets/javascripts
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/bootstrap-sass-3.0.2.1/vendor/assets/stylesheets
  /home/prasad/.rvm/gems/ruby-2.0.0-p247/gems/bootstrap-sass-3.0.2.1/vendor/assets/stylesheets

（在/home/prasad/projects/website/app/assets/stylesheets/application.css.scss:16）

我引用Twitter bootstrap: do I need both bootstrap-sass and twitter-bootstrap-rails gems?但无法修复错误 . 谢谢你的建议 .