title: Zombie SharedDataMiddleware on Python Heroku
body: <p>I'm setting up a Flask app on Heroku. Everything is working fine until I added static files. I'm using this:</p>
  
  <pre><code>from werkzeug import SharedDataMiddleware
  app = Flask(__name__)
  app.wsgi_app = SharedDataMiddleware(app.wsgi_app, {'/static': os.path.join(os.path.dirname(__file__), 'static') })
  </code></pre>
  
  <p>The first time I deploy the app, the appropriate files in the ./static will be available at herokuapp.com/static. But after that initial deploy, the files never change on Heroku. If I change the last line to:</p>
  
  <pre><code>app.wsgi_app = SharedDataMiddleware(app.wsgi_app, {'/assets': os.path.join(os.path.dirname(__file__), 'static') })
  </code></pre>
  
  <p>a new URL for the static files, herokuapp.com/assets, then I can see the updated files.</p>
  
  <p>It seems like a mirror of the files gets stuck in the system. I've changed it four times and can access all of the URLs still.</p>