title: RVM install 1.9.2-head ERROR
body: <p>I am using RVM to maintain ROR enviroment:</p>
  
  <p>But when I am trying to install ruby-head , it gives me error messages like this:</p>
  
  <pre><code>shanan@shanan-ThinkPad:~$ rvm install 1.9.2-head
  /home/shanan/.rvm/rubies/ruby-1.9.2-head, 
    this may take a while depending on your cpu(s)...
  
  ruby-1.9.2-head - #fetching 
  Cloning from https://github.com/ruby/ruby.git, this may take a while depending on your connection...
  Cloning into /home/shanan/.rvm/repos/ruby-1.9.2-head...
  fatal: Unable to find remote helper for 'https'
  cloning from https://github.com/ruby/ruby.git failed, now attempting to clone from https://github.com/ruby/ruby.git, this may take a while depending on your connection...
  Cloning into /home/shanan/.rvm/repos/ruby-1.9.2-head...
  fatal: Unable to find remote helper for 'https'
  There has been an error while trying to fetch the repository.               
  Halting the installation.
  There has been an error fetching the ruby interpreter. Halting the installation.
  shanan@shanan-ThinkPad:~$ 
  </code></pre>
  
  <p><strong>I am using git 1.7.4, and other dependencies are correctly installed and configured.
  I really do not know why and how to solve this problem. Can you help me?</strong></p>