title: Error installing rmagick: ERROR: Failed to build gem native extension
body: <p>I am trying to install RmMagic using the below command:</p>
  
  <pre>gem install rmagick -v=2.12.2</pre>
  
  <p>After running this command i get some error :</p>
  
  <pre>
  Temporarily enhancing PATH to include DevKit...
  Building native extensions.  This could take a while...
  ERROR:  Error installing rmagick:
          ERROR: Failed to build gem native extension.
  
  
          D:/ruby/bin/ruby.exe extconf.rb
  checking for Ruby version >= 1.8.5... yes
  Invalid drive specification.
  Unable to get ImageMagick version
  *** 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}/lib
          --with-make-prog
          --without-make-prog
          --srcdir=.
          --curdir
          --ruby=D:/ruby/bin/ruby
  
  
  Gem files will remain installed in D:/ruby/lib/ruby/gems/1.8/gems/rmagick-2
  .12.2 for inspection.
  Results logged to D:/ruby/lib/ruby/gems/1.8/gems/rmagick-2.12.2/ext/RMagick
  /gem_make.out
  </pre>
  
  <p>Please help me in this regard. Thanks in advance.</p>