title: Installed gem not showing in gem list
body: <p>I am confused about adding gems. I listed the gems that are installed:</p>
  
  <pre><code>mypath$ gem list
  
  *** LOCAL GEMS ***
  
  bouncy-castle-java (1.5.0147)
  cassandra-driver (2.1.3 java)
  cql-rb (2.0.4)
  domain_name (0.5.23)
  http-cookie (1.0.2)
  httpclient (2.6.0.1)
  imagesize (0.1.1)
  ione (1.2.0)
  jruby-openssl (0.9.7 java, 0.9.6 java)
  json (1.8.2 java)
  mime-types (2.4.3)
  net-scp (1.2.1)
  net-ssh (2.9.2)
  netrc (0.10.2)
  rest-client (1.8.0, 1.7.2)
  ruby-debug-base (0.10.5.rc10 java, 0.10.4 java)
  ruby-debug-ide (0.4.24)
  soap4r (1.5.8)
  unf (0.1.4 java)
  xml-simple (1.1.5)
  mypath$ 
  </code></pre>
  
  <p>I wanted to add the minitest-junit gem to the installed gems so I installed it and it said that the gem installation was successful. </p>
  
  <pre><code>myPath$sudo gem install minitest-junit
  Successfully installed minitest-junit-0.2.0
  1 gem installed
  Installing ri documentation for minitest-junit-0.2.0...
  Installing RDoc documentation for minitest-junit-0.2.0...
  mypath$ 
  </code></pre>
  
  <p>When I tried to use it I got errors that the gem not known, so I ran <code>gem list</code> command again and the gem was not listed:</p>
  
  <pre><code>mypath$ gem list
  
  *** LOCAL GEMS ***
  
  bouncy-castle-java (1.5.0147)
  cassandra-driver (2.1.3 java)
  cql-rb (2.0.4)
  domain_name (0.5.23)
  http-cookie (1.0.2)
  httpclient (2.6.0.1)
  imagesize (0.1.1)
  ione (1.2.0)
  jruby-openssl (0.9.7 java, 0.9.6 java)
  json (1.8.2 java)
  mime-types (2.4.3)
  net-scp (1.2.1)
  net-ssh (2.9.2)
  netrc (0.10.2)
  rest-client (1.8.0, 1.7.2)
  ruby-debug-base (0.10.5.rc10 java, 0.10.4 java)
  ruby-debug-ide (0.4.24)
  soap4r (1.5.8)
  unf (0.1.4 java)
  xml-simple (1.1.5)
  mypath$ 
  </code></pre>
  
  <p>What am I missing here? Shouldn't there be an error if the gem does not install? </p>