title: After installing rbenv and changing Ruby version, Rake no longer runs
body: <p>After installing Rbenv and Ruby 1.9.2 and 1.8.7, and setting the current project to use 1.9.2 (it previously used 1.8.7), Rake will no longer run.  Running <code>rake routes</code> gives the messages:</p>
  
  <pre><code>Could not find rake-0.8.7 in any of the sources
  Run `bundle install` to install missing gems.
  </code></pre>
  
  <p>This after runing <code>bundle install</code>.</p>
  
  <p>Trying <code>bundle exec rake routes</code> (which is the method used prior to installing Rbenv), produces the following errors:</p>
  
  <pre><code>NOTE: Gem.source_index is deprecated, use Specification. It will be removed on or after 2011-11-01.
  Gem.source_index called from /Library/Ruby/Gems/1.8/gems/bundler-1.0.9/lib/bundler/shared_helpers.rb:3.
  Invalid gemspec in [/Users/jackrg/Documents/Novelty-Stats/vendor/local/ruby/1.8/specifications/jquery-rails-1.0.19.gemspec]: invalid date format in specification: "2011-11-26 00:00:00.000000000Z"
  Invalid gemspec in [/Users/jackrg/Documents/Novelty-Stats/vendor/local/ruby/1.8/specifications/tilt-1.3.3.gemspec]: invalid date format in specification: "2011-08-25 00:00:00.000000000Z"
  NOTE: Gem.source_index is deprecated, use Specification. It will be removed on or after 2011-11-01.
  Gem.source_index called from /Library/Ruby/Gems/1.8/gems/bundler-1.0.9/lib/bundler/source.rb:161.
  NOTE: Gem::SourceIndex#each is deprecated with no replacement. It will be removed on or after 2011-11-01.
  Gem::SourceIndex#each called from /Library/Ruby/Gems/1.8/gems/bundler-1.0.9/lib/bundler/source.rb:161.
  Could not find rake-0.8.7 in any of the sources
  </code></pre>
  
  <p>Note that the application itself runs without issue in development (<code>rails c</code>, <code>rails s</code>, etc.).</p>
  
  <p>Also note that <code>gem list</code> lists rake (0.8.7) as a local gem.</p>
  
  <p>If I change the gemfile to request rake version 0.9.2 and then update the bundle (bundle update rake), I get the same errors except that they now refer to version 0.9.2 of rake instead of 0.8.7.</p>