title: Can't activate rack (~> 1.4.0, runtime) already activated rack-1.5.0
body: <p>I've been looking for an answer to this for over a day now, and searched StackOverflow thoroughly.</p>
  
  <p>I understand the conflict that's happening, and I should just uninstall the version of Rack I don't need, but here's the thing. I'm developing on Koding (<a href="http://koding.com" rel="nofollow">http://koding.com</a>) and I don't have access to system level gems.</p>
  
  <p>Rails was working before, I installed the mongo gem, removed it, and installed mysql2 gem.</p>
  
  <pre><code>bash4.1$ rails
  /usr/lib/ruby/site_ruby/1.8/rubygems.rb:233:in `activate': can't activate rack (~&gt; 1.4.0, runtime) for ["actionpack-3.2.11", "railties-3.2.11"
  ], already activated rack-1.5.0 for ["rack-ssl-1.3.2", "railties-3.2.11"] (Gem::LoadError)
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:249:in `activate'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `each'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `activate'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:249:in `activate'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `each'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:248:in `activate'
  from /usr/lib/ruby/site_ruby/1.8/rubygems.rb:1082:in `
  from /usr/bin/rails:18
  </code></pre>
  
  <p>I've wiped my directory clean, tried using RVM, and still nothing. Any ideas?</p>
  
  <p>Thanks!</p>