title: GUnicorn throws error while loading python flask app: no such option as -b
body: <pre><code>    #:return: Flask app
  app = Flask(__name__, instance_relative_config=True)
  
  if __name__ == "__main__":
      app.run(debug=True,host='0.0.0.0', port=8000)
  </code></pre>
  
  <p>GUnicorn start command:-</p>
  
  <pre><code>gunicorn "app:app" -b 0.0.0.0:8000
  </code></pre>
  
  <p>Error:-</p>
  
  <pre><code>[2020-04-06 12:35:09 +0000] [62] [INFO] Worker exiting (pid: 62)
  [2020-04-06 12:35:09 +0000] [63] [INFO] Booting worker with pid: 63
  Usage: gunicorn [OPTIONS]
  Try 'gunicorn --help' for help.
  Error: no such option: -b
  </code></pre>
  
  <p>The GUnicorn goes in an infinite loop while starting up. Can someone please explain me what I'm missing?</p>