title: rake aborted! cannot load such file -- yard
body: <p>I have been trying to add a vagrant plugin (<a href="https://github.com/schisamo/vagrant-omnibus" rel="noreferrer">https://github.com/schisamo/vagrant-omnibus</a>) from source. I downloaded it, did "bundle install", which went smooth. But when I did "rake install", it showed me the following error:</p>
  
  <pre><code>rake aborted!
  cannot load such file -- yard
  </code></pre>
  
  <p>Here is the full error log with trace:</p>
  
  <pre><code>rake aborted!
  cannot load such file -- yard
  /root/chef-solo-example/vagrant-omnibus-master/Rakefile:5:in `require'
  /root/chef-solo-example/vagrant-omnibus-master/Rakefile:5:in `&lt;top (required)&gt;'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/rake_module.rb:25:in `load'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/rake_module.rb:25:in `load_rakefile'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:589:in `raw_load_rakefile'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:89:in `block in load_rakefile'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:88:in `load_rakefile'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:72:in `block in run'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
  /usr/share/gems/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
  /usr/share/gems/gems/rake-10.0.4/bin/rake:33:in `&lt;top (required)&gt;'
  /bin/rake:23:in `load'
  /bin/rake:23:in `&lt;main&gt;'
  </code></pre>
  
  <p>Here is the gem list:</p>
  
  <pre><code>*** LOCAL GEMS ***
  
  archive-tar-minitar (0.5.2)
  ast (1.1.0)
  bigdecimal (1.2.0)
  bundler (1.3.1)
  chef (11.8.2)
  chef-zero (1.7.2)
  coderay (1.1.0)
  diff-lcs (1.2.5)
  erubis (2.7.0)
  hashie (2.0.5)
  highline (1.6.20)
  io-console (0.4.2)
  ipaddress (0.8.0)
  json (1.7.7)
  knife-solo (0.4.1)
  librarian (0.1.0)
  librarian-chef (0.0.2)
  method_source (0.8.2)
  mime-types (1.16)
  mixlib-authentication (1.3.0)
  mixlib-cli (1.4.0)
  mixlib-config (2.1.0)
  mixlib-log (1.6.0)
  mixlib-shellout (1.3.0)
  moneta (0.7.20, 0.7.0, 0.6.0)
  net-http-persistent (2.8)
  net-ssh (2.7.0)
  net-ssh-gateway (1.2.0)
  net-ssh-multi (1.2.0, 1.1)
  ohai (6.20.0)
  parser (2.0.0)
  powerpack (0.0.9, 0.0.6)
  pry (0.9.12.4)
  psych (2.0.0)
  puma (1.6.0)
  rack (1.5.2)
  rainbow (1.1.4)
  rake (10.0.4)
  rake-compiler (0.8.3)
  rdoc (4.0.1)
  rest-client (1.6.7)
  rspec (2.14.1)
  rspec-core (2.14.0)
  rspec-expectations (2.14.0)
  rspec-mocks (2.14.0)
  rubocop (0.15.0)
  slop (3.4.7)
  systemu (2.6.0, 2.5.2)
  thor (0.17.0)
  yajl-ruby (1.1.0)
  yard (0.8.7.3)
  </code></pre>
  
  <p>Any idea what could be causing this error?</p>