title: gem install mysql failure in Snow Leopard
body: <p>I successfully installed MySql x86_64 in Snow Leopard and Ruby and Ruby Gems seems to be installed properly:</p>
  
  <pre>$ which mysql
  /usr/local/mysql/bin/mysql
  $ which ruby
  /usr/bin/ruby
  $ which gem
  /usr/bin/gem
  $ mysql
  Your MySQL connection id is 404
  Server version: 5.1.37 MySQL Community Server (GPL)
  $ ruby -v
  ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0]
  $ gem -v
  1.3.5
  </pre>
  
  <p>Unfortunatly I get an error installing mysql gem:</p>
  
  <pre>$ sudo gem update --system
  ...
  $ sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
  Building native extensions.  This could take a while...
  ERROR:  Error installing mysql:
      ERROR: Failed to build gem native extension.
  
  /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb --with-mysql-config=/usr/local/mysql/bin/mysql_config
  mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h
  
  
  Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/mysql-2.8.1 for inspection.
  </pre>