由于错误，无法创建rails应用程序
这就是我正在做的事情
rails new ffffff /usr/lib/ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find railties (>= 0) amongst [activemodel-4.0.0.beta1, activesupport-4.0.0.beta1, atomic-1.0.1, backports-3.1.1, bcrypt-ruby-3.0.1, bson-1.8.3, bson_ext-1.8.3, builder-3.1.4, bundler-1.3.1, chunky_png-1.2.7, coderay-1.0.9, compass-0.12.2, daemons-1.1.9, eventmachine-1.0.3, exceptional-2.0.33, fssm-0.2.10, haml-4.0.0, i18n-0.6.4, jsmin-1.0.1, mail-2.5.3, method_source-0.8.1, mime-types-1.21, minitest-4.6.2, moped-1.4.3, multi_json-1.6.1, nokogiri-1.5.6, origin-1.0.11, polyglot-0.3.3, pony-1.4, pry-0.9.12, pry-nav-0.2.3, rack-1.5.2, rack-mount-0.8.3, rack-protection-1.5.0, rack-test-0.6.2, rack-timeout-0.0.3, rake-10.0.3, rubygems-bundler-1.1.1, rvm-1.11.3.6, sass-3.2.7, shotgun-0.9, sinatra-1.3.5, sinatra-assetpack-0.1.7, sinatra-contrib-1.3.2, sinatra-flash-0.3.0, sinatra-support-1.2.2, slop-3.4.4, thin-1.5.0, thread_safe-0.1.0, tilt-1.3.5, time-lord-1.0.1, treetop-1.4.12, tzinfo-0.3.37] (Gem::LoadError) from /usr/lib/ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec' from /usr/lib/ruby/1.9.1/rubygems.rb:1231:in `gem' from /usr/local/bin/rails:22:in `' 我只安装了ruby 2.0
rvm list rvm rubies =* ruby-2.0.0-p0 [ x86_64 ] # => - current # =* - current && default # * - default
我该如何解决？
好像你没有安装铁路：
gem install railties