title: Installing rmagick gem fails on Mac OS X Lion
body: <p>On MAC OS X LION while install rmagic gem, I am getting desperately this error:</p>
  
  <pre><code>    Installing rmagick (2.13.1) with native extensions 
      Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  
              /Users/joel/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb 
      checking for Ruby version &gt;= 1.8.5... yes
      checking for gcc... yes
      checking for Magick-config... yes
      checking for ImageMagick version &gt;= 6.4.9... yes
      checking for HDRI disabled version of ImageMagick... yes
      checking for stdint.h... *** 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=/Users/joel/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
      /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:368:in `try_do': The complier failed to generate an executable file. (RuntimeError)
      You have to install development tools first.
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:452:in `try_cpp'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:834:in `block in have_header'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:693:in `block in checking_for'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block (2 levels) in postpone'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block in postpone'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:276:in `postpone'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:692:in `checking_for'
          from /Users/joel/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:833:in `have_header'
          from extconf.rb:193:in `&lt;main&gt;'
  
  
      Gem files will remain installed in /Users/joel/.rvm/gems/ruby-1.9.2-p290/gems/rmagick-2.13.1 for inspection.
      Results logged to /Users/joel/.rvm/gems/ruby-1.9.2-p290/gems/rmagick-2.13.1/ext/RMagick/gem_make.out
      An error occured while installing rmagick (2.13.1), and Bundler cannot continue.
      Make sure that `gem install rmagick -v '2.13.1'` succeeds before bundling.
  </code></pre>
  
  <p>Used this installer to install ImageMagick before hand</p>
  
  <p><a href="http://cactuslab.com/imagemagick/" rel="nofollow">http://cactuslab.com/imagemagick/</a> 
  picked ImageMagick 6.7.3-2 for Mac OS X Lion </p>
  
  <p>I spend a couple of hours on this, hope someone can give me a lead on how to resolve this.</p>
  
  <p>ADDITIONAL ERROR MESSAGE:</p>
  
  <pre><code> Can't install RMagick 2.13.1. Can't find MagickWand.h.
  </code></pre>