title: Errno::EACCES: Permission denied @ rb_sysopen
body: <p><strong>when I try to run gem install json -v 1.8.3</strong></p>
  
  <p>ERROR:  While executing gem ... (Errno::EACCES)
      Permission denied @ rb_sysopen - /home/ulap10/.gem/gems/json-1.8.3/tests/test_json.rb</p>
  
  <p><strong>I tried to fix this by reclaiming ownership using</strong> - <code>sudo chown  -R ulap10 /home/ulap10/.gem/gems/json-1.8.3/tests/test_json.rb</code>  but it didn't work.</p>
  
  <p>How can I resolve this?</p>