title: How do you communicate between Rake tasks?
body: <p>Let's say I have a target who needs to compile some files. That target has another target as a prerequisite, one that obtains the files.
  Let's say this:</p>
  
  <pre><code>task :obtain do
    # obtain files from somewhere
  end
  
  task :compile =&gt; :obtain do
    # do compilation
  end
  </code></pre>
  
  <p>Let's say that the <code>:obtain</code> target doesn't always places the files in the same folder. How would I pass <code>:compile</code> the path that <code>:obtain</code> found? Environment variables?</p>