我第一次学习RoR而且我被困在本教程的这一部分 http://www.railstutorial.org/book/static_pages#sec-first_tests
特别是在我应该配置这个gem文件的开头。我知道还有其他更多的最新版本，但我试图按照这个特定版本的教程。我的gemfile与链接中显示的相同。
当我跑步时：bundle install --without production我得到：
Bundler could not find compatible versions for gem "sprockets-rails":
In snapshot (Gemfile.lock):
sprockets-rails (2.1.3)
In Gemfile:
rails (= 4.0.5) ruby depends on
sprockets-rails (~> 2.0.0) ruby
Running `bundle update` will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.
我试过bundle update，但我得到了：
An error occurred while installing nokogiri (1.6.2.1), and Bundler cannot
continue.
Make sure that `gem install nokogiri -v '1.6.2.1'` succeeds before bundling.
我尝试了gem install nokogiri -v '1.6.1'，但得到了：
ERROR: Error installing nokogiri:
ERROR: Failed to build gem native extension.
/Users/bradfordli/.rvm/rubies/ruby-2.0.0-p481/bin/ruby extconf.rb
Building nokogiri using packaged libraries.
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libiconv is missing. please visit http://nokogiri.org/tutorials/installing_nokogiri.html for help with installing dependencies.
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*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.