title: Rails console can't find Rake, but Bundler installed it
body: <p>Rake 12.3.1 is in the Gemfile, and installed:</p>
  
  <pre><code>/app # bundle install | grep rake
  Using rake 12.3.1
  
  /app # grep rake Gemfile.lock
        rake (&gt;= 0.8.7)
      rake (12.3.1)
  
  /app # bundle exec gem list | grep rake
  rake (12.3.1)
  </code></pre>
  
  <p>Bundler thinks all is well:</p>
  
  <pre><code>/app # bundle check
  The Gemfile's dependencies are satisfied
  </code></pre>
  
  <p>A plain <code>bundle exec ruby</code> loads it ok:</p>
  
  <pre><code>/app # bundle exec ruby -e'require "rake"; p Rake::VERSION'
  "12.3.1"
  </code></pre>
  
  <p>But, a Rails console can't find it:</p>
  
  <pre><code>/app # bin/rails c
  Could not find rake-12.3.1 in any of the sources
  Run `bundle install` to install missing gems.
  
  /app # bundle exec bin/rails c
  Could not find rake-12.3.1 in any of the sources
  Run `bundle install` to install missing gems.
  </code></pre>
  
  <p>What am I missing?</p>