title: xontrib autojump freezes xonsh shell
body: <p>I'm using MiniConda with xonsh installed.
  Running print(sys.version) produces:</p>
  
  <pre><code>3.7.4 (default, Aug  9 2019, 18:34:13) [MSC v.1915 64 bit (AMD64)]
  </code></pre>
  
  <p>I'm not sure which version of xonsh I'm using, but I installed it yesterday (Jan 29, 2020) and it's whatever the conda command got.</p>
  
  <p>When I run <code>xontrib list</code> I get</p>
  
  <pre><code>apt_tabcomplete     not-installed  not-loaded
  autojump            installed      not-loaded &lt;======= NOTE!
  autovox             installed      not-loaded
  autoxsh             not-installed  not-loaded
  avox                not-installed  not-loaded
  bashisms            installed      not-loaded
  base16_shell        not-installed  not-loaded
  coreutils           installed      not-loaded
  direnv              not-installed  not-loaded
  distributed         installed      not-loaded
  docker_tabcomplete  not-installed  not-loaded
  free_cwd            installed      loaded
  </code></pre>
  
  <p>The key point being that autojump <em>is</em> installed, but it is <em>not</em> loaded.</p>
  
  <p>When I run <code>xontrib load -v autojump</code> I get a single message, and then the shell freezes up (the cursor is still blinking, but the shell isn't doing anything).  The message is:</p>
  
  <pre><code>loading xontrib 'autojump'
  </code></pre>
  
  <p>I'm taking care to use the Python stuff from the MiniConda install (not my other copies of Python that I've got).</p>
  
  <p>Would anyone have any ideas about how to debug this?  I'd love to find a way to get more information about what's going on and why it's freezing.</p>
  
  <p>Thanks!</p>