title: Turbogears2: App not starting as sub-package
body: <p>I'm trying to deploy TurboGears as the sub-package <code>frontend</code> of my main application <code>MainApp</code>. Following, the structure of my project:</p>
  <pre><code>.
  ├── MainApp
  │   ├── MainApp.egg-info
  │   ├── backend
  │   ├── frontend
  │   └── __init__.py
  ├── LICENSE.txt
  ├── MANIFEST.in
  ├── README.md
  ├── development.ini
  ├── setup.cfg
  ├── setup.py
  ├── test.ini
  </code></pre>
  <p>Unfortunately, I always get an error when trying to start it with <code>gearbox serve --reload --debug</code> in the project folder:</p>
  <pre><code>pkg_resources.DistributionNotFound: The 'MainApp.frontend' distribution was not found and is required by the application
  </code></pre>
  <p>I understand that this is due to the definition in the <code>development.ini</code>:</p>
  <pre><code>[app:main]
  use = egg:MainApp.frontend
  </code></pre>
  <p>I tried different alternatives, calling <code>egg:MainApp</code> or <code>egg:frontend</code>, also inside the <code>MainApp</code> folder with the <code>development.ini</code> copied over - nothing worked. What am I missing? Is this even possible?</p>
  <p>Thanks you.</p>