title: Flask with a webserver breaks all sessions?
body: <p>For example, this code:</p>
  
  <pre><code>from flask import session
  
  @app.route('/is_logged_in/')
  def is_logged_in():
    return 'user' in session
  </code></pre>
  
  <p>It runs fine for me when running Flask's development server, but it throws a <code>500</code> error with <em>any</em> webserver setup (FastCGI, uWSGI, etc.) on any server (Apache, nginx, Lighttpd).</p>
  
  <p>Anybody know why?</p>
  
  <hr>
  
  <p>My actual code is on GitHub, if it matters.</p>
  
  <p>It works flawlessly when running with Flask's internal server, but I can't get any session variables to work with a production webserver: <a href="https://github.com/Blender3D/Webminal/blob/master/server.py" rel="nofollow">https://github.com/Blender3D/Webminal/blob/master/server.py</a></p>