title: ImportError: cannot import name sandbox
body: <p>Over the past couple days, this has started cropping up whenever I run <code>dev_appserver.py</code>:</p>
  
  <pre><code>from google.appengine.tools.devappserver2.python import sandbox
  ImportError: cannot import name sandbox
  </code></pre>
  
  <p>Since I was primarily coming across this in the setup of a new environment, I figured it must be a mistake of mine during setup. After enough head-scratching over the past 3 hours, I figured it couldn't be in the new setup, so I loaded up <code>dev_appserver.py</code> in a known-to-be-working environment.</p>
  
  <p>Yet again:</p>
  
  <pre><code>from google.appengine.tools.devappserver2.python import sandbox
  ImportError: cannot import name sandbox
  </code></pre>
  
  <p>None of my app code had been changed, so it <em>had</em> to be something else.</p>