title: Install mysql2 gem on Snow Leopard for Rails 3 with rvm
body: <p>I have recently upgraded to Rails 3 and created a new application with Rails 3.0.3, but I keep getting an error</p>
  
  <pre>
  Macintosh:$ rails server
  => Booting WEBrick
  => Rails 3.0.3 application starting in development on http://0.0.0.0:3000
  => Call with -d to detach
  => Ctrl-C to shutdown server
  [2010-11-28 11:32:47] INFO  WEBrick 1.3.1
  [2010-11-28 11:32:47] INFO  ruby 1.8.7 (2010-04-19) [i686-darwin10.4.0]
  [2010-11-28 11:32:47] INFO  WEBrick::HTTPServer#start: pid=1055 port=3000
  
  
  Started GET "/" for 127.0.0.1 at Sun Nov 28 11:32:52 +0000 2010
  
  RuntimeError (!!! Missing the mysql2 gem. Add it to your Gemfile: gem 'mysql2'):
  
  
  </pre>
  
  <p>I have a 64 bits machine. Errors are only on documentation and looked like the gem was installed correctly.</p>
  
  <pre>
  Macintosh:$ env ARCHFLAGS="-arch i386" gem install mysql2 -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
  Building native extensions.  This could take a while...
  Successfully installed mysql2-0.2.6
  1 gem installed
  Installing ri documentation for mysql2-0.2.6...
  Enclosing class/module 'mMysql2' for class Client not known
  Building YARD (yri) index for mysql2-0.2.6...
  Installing RDoc documentation for mysql2-0.2.6...
  Enclosing class/module 'mMysql2' for class Client not known
  
  </pre>
  
  <p>I have added the gem in my GemFile</p>
  
  <pre>
  source 'http://rubygems.org'
  
  gem 'rails', '3.0.3'
  gem 'mysql2'
  gem 'sqlite3-ruby', :require => 'sqlite3'
  
  </pre>
  
  <p>My GemFile.lock looks like this</p>
  
  <pre>
  GEM
    remote: http://rubygems.org/
    specs:
      abstract (1.0.0)
      actionmailer (3.0.3)
        actionpack (= 3.0.3)
        mail (~> 2.2.9)
      actionpack (3.0.3)
        activemodel (= 3.0.3)
        activesupport (= 3.0.3)
        builder (~> 2.1.2)
        erubis (~> 2.6.6)
        i18n (~> 0.4)
        rack (~> 1.2.1)
        rack-mount (~> 0.6.13)
        rack-test (~> 0.5.6)
        tzinfo (~> 0.3.23)
      activemodel (3.0.3)
        activesupport (= 3.0.3)
        builder (~> 2.1.2)
        i18n (~> 0.4)
      activerecord (3.0.3)
        activemodel (= 3.0.3)
        activesupport (= 3.0.3)
        arel (~> 2.0.2)
        tzinfo (~> 0.3.23)
      activeresource (3.0.3)
        activemodel (= 3.0.3)
        activesupport (= 3.0.3)
      activesupport (3.0.3)
      arel (2.0.4)
      builder (2.1.2)
      erubis (2.6.6)
        abstract (>= 1.0.0)
      i18n (0.4.1)
      mail (2.2.10)
        activesupport (>= 2.3.6)
        i18n (~> 0.4.1)
        mime-types (~> 1.16)
        treetop (~> 1.4.8)
      mime-types (1.16)
      mysql2 (0.2.6)
      polyglot (0.3.1)
      rack (1.2.1)
      rack-mount (0.6.13)
        rack (>= 1.0.0)
      rack-test (0.5.6)
        rack (>= 1.0)
      rails (3.0.3)
        actionmailer (= 3.0.3)
        actionpack (= 3.0.3)
        activerecord (= 3.0.3)
        activeresource (= 3.0.3)
        activesupport (= 3.0.3)
        bundler (~> 1.0)
        railties (= 3.0.3)
      railties (3.0.3)
        actionpack (= 3.0.3)
        activesupport (= 3.0.3)
        rake (>= 0.8.7)
        thor (~> 0.14.4)
      rake (0.8.7)
      sqlite3-ruby (1.2.4)
      thor (0.14.6)
      treetop (1.4.9)
        polyglot (>= 0.3.1)
      tzinfo (0.3.23)
  
  PLATFORMS
    ruby
  
  DEPENDENCIES
    mysql2
    rails (= 3.0.3)
    sqlite3-ruby
  
  </pre>
  
  <p>Gem list</p>
  
  <pre>
  Macintosh:$ gem list
  
  *** LOCAL GEMS ***
  
  abstract (1.0.0)
  actionmailer (3.0.3)
  actionpack (3.0.3)
  activemodel (3.0.3)
  activerecord (3.0.3)
  activeresource (3.0.3)
  activesupport (3.0.3)
  acts_as_ferret (0.4.4)
  arel (2.0.4)
  builder (3.0.0, 2.1.2)
  bundler (1.0.7)
  capistrano (2.5.9)
  dnssd (1.3)
  erubis (2.6.6)
  fastthread (1.0.7)
  gnuplot (2.2)
  highline (1.6.1, 1.5.1)
  hpricot (0.8.1)
  i18n (0.4.2, 0.4.1)
  libxml-ruby (1.1.3)
  linecache (0.43)
  mail (2.2.10)
  memcache-client (1.8.5, 1.7.6)
  memcached (0.17.5)
  mime-types (1.16)
  mysql2 (0.2.6)
  net-scp (1.0.4, 1.0.2)
  net-sftp (2.0.5, 2.0.2)
  net-ssh (2.0.23, 2.0.15)
  net-ssh-gateway (1.0.1)
  polyglot (0.3.1)
  rack (1.2.1, 1.0.1, 1.0.0)
  rack-mount (0.6.13)
  rack-test (0.5.6)
  rails (3.0.3)
  railties (3.0.3)
  rake (0.8.7, 0.8.4)
  rcov (0.9.9, 0.9.8)
  rdoc (2.5.11)
  RedCloth (4.2.2)
  rmagick (2.12.2)
  ruby-debug-base (0.10.3)
  ruby-debug-ide (0.4.5)
  rubygems-update (1.3.7, 1.3.5, 1.3.3)
  rvm (1.1.1)
  sqlite3-ruby (1.3.2, 1.2.4)
  test-spec (0.10.0)
  text-format (1.0.0)
  text-hyphen (1.0.0)
  thor (0.14.6)
  treetop (1.4.9)
  tzinfo (0.3.23)
  yard (0.5.8)
  
  </pre>
  
  <p>My Mysql is up and running:</p>
  
  <pre>
  Macintosh:$ mysql -uroot
  Welcome to the MySQL monitor.  Commands end with ; or \g.
  Your MySQL connection id is 1
  Server version: 5.1.53 MySQL Community Server (GPL)
  
  Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
  This software comes with ABSOLUTELY NO WARRANTY. This is free software,
  and you are welcome to modify and redistribute it under the GPL v2 license
  
  Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  
  mysql> 
  
  </pre>
  
  <p>This is all I have in my brand new application, but I'm still getting the missing mysql2 gem problem.</p>
  
  <p>I have Snow Leopard 10.6.5 with X Code 3.2.4 installed.</p>
  
  <p>Any idea?</p>
  
  <p>Thanks in advance!</p>