title: cargo always starts with " Blocking waiting for file lock on build directory"
body: <p>I recently installed rustup on my Windows machine and incorporated it into Atom as my editor. Everything works fine, but as soon as I do a <code>cargo run</code> on my project, the first thing that Cargo says is:</p>
  
  <pre class="lang-none prettyprint-override"><code> Blocking waiting for file lock on build directory
  </code></pre>
  
  <p>This blocks the whole process for about a minute before the actual compile and run starts. As far as I remember this did not happen before (I use Cargo under OS X but without rustup). </p>
  
  <p>Is there any way to disable this or at least reduce the timeout?</p>