title: How to resolve inconsistent package warnings in conda?
body: <p>Newer versions of Conda provide the user with more detailed information about inconsistent packages casuing conflict with the environment. One such package in my conda env is the <code>_nb_ext_conf</code> which according to anaconda cloud, is the latest  0.4.0 installed in my system and even then I'm receiving this warning when trying to install/update a module:</p>
  <pre><code>The environment is inconsistent, please check the package plan carefully
  The following packages are causing inconsistency:
   - defaults/osx-64::_nb_ext_conf==0.4.0=py36_1
  </code></pre>
  <p>This package cannot be removed, since its required by jupyterlab as well as notebook. I'm not sure if it's causing serious conflict since I haven't yet experienced anything getting broken, but I would still want to resolve this inconsistency. Is there a way I could fix it? I searched for similar questions in conda's issues section in github, but did not come across anything similar.</p>