title: Unable to install therubyracer gem
body: <p>I installed <strong>libv8</strong> gem seperately without a hitch, but when I try to install therubyracer gem I get the following error:</p>
  
  <pre><code>Building native extensions.  This could take a while...
  ERROR:  Error installing therubyracer:
      ERROR: Failed to build gem native extension.
  
          /usr/bin/ruby extconf.rb
  checking for main() in -lpthread... yes
  Warning! Unable to load libv8 ~&gt; 3.16.14.
  *** extconf.rb failed ***
  Could not create Makefile due to some reason, probably lack of
  necessary libraries and/or headers.  Check the mkmf.log file for more
  details.  You may need configuration options.
  
  Provided configuration options:
      --with-opt-dir
      --without-opt-dir
      --with-opt-include
      --without-opt-include=${opt-dir}/include
      --with-opt-lib
      --without-opt-lib=${opt-dir}/
      --with-make-prog
      --without-make-prog
      --srcdir=.
      --curdir
      --ruby=/usr/bin/ruby
      --with-pthreadlib
      --without-pthreadlib
      --enable-debug
      --disable-debug
  extconf.rb:32:in `&lt;main&gt;': undefined method `configure_makefile' for Libv8:Module (NoMethodError)
  
  
  Gem files will remain installed in /home/thecodehitman/ruby/gems/gems/therubyracer-0.12.1 for inspection.
  Results logged to /home/thecodehitman/ruby/gems/gems/therubyracer-0.12.1/ext/v8/gem_make.out
  </code></pre>
  
  <p>Not sure what to do.</p>