title: Flask-Migrate command 'flask db init' can't find app file
body: <p>Firstly, I'm following the Python Flask tutorial posted here: <a href="https://scotch.io/tutorials/build-a-crud-web-app-with-python-and-flask-part-one" rel="nofollow noreferrer">https://scotch.io/tutorials/build-a-crud-web-app-with-python-and-flask-part-one</a>.</p>
  
  <p>Everything was working smoothly up to the 'Migration' section where executing:</p>
  
  <pre><code>$ flask db init
  </code></pre>
  
  <p>... failed with the following error:</p>
  
  <pre><code>Usage: flask db init [OPTIONS]
  
  Error: The file/path provided (run) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py
  </code></pre>
  
  <p>I know the $FLASK_APP env variable is set because this command executes fine:</p>
  
  <pre><code>$ flask run
  </code></pre>
  
  <p>Can anyone suggest why this executes fine when running the app, but not when trying to create the migration repository?</p>
  
  <p>The closest I can find elsewhere on the subject is here: <a href="https://stackoverflow.com/questions/37650208/flask-cant-find-app-file">Flask can&#39;t find app file</a>, but pre-pending with <code>python -m</code> isn't working in either case for me here.</p>