title: Getting a series of errors when trying to update Conda and Python
body: <p>I neglected to update my conda installation for a long time.  It was version 4.1-ish, running Python 3.5.2.  I finally decided to make the switch to Python 3.9, but I have been having some trouble getting everything to update.  I started by running commands like</p>
  <pre><code>conda update conda
  conda update anaconda
  conda update python
  conda update -all
  </code></pre>
  <p>repeatedly and made a fair amount of progress, but eventually conda reached a steady state and won't go any further.</p>
  <p>Now I have conda version 4.5.11 and python 3.5.6.  When I run <code>conda update conda</code> or <code>conda update -n base -c defaults conda</code>, it returns</p>
  <pre><code>==&gt; WARNING: A newer version of conda exists. &lt;==
    current version: 4.5.11
    latest version: 4.13.0
  </code></pre>
  <p>but then doesn't install it.</p>
  <p>When I try <code>conda install conda=4.13.0</code>, I get</p>
  <pre><code>Solving environment: failed
  
  UnsatisfiableError: The following specifications were found to be in conflict:
    - conda=4.13.0
    - pymc
  Use &quot;conda info &lt;package&gt;&quot; to see the dependencies for each package.
  </code></pre>
  <p>Similarly, when I try <code>conda install python=3.9</code> or <code>conda install python=3.7</code>, it gives me</p>
  <pre><code>UnsatisfiableError: The following specifications were found to be in conflict:
    - healpy -&gt; python=3.5 -&gt; libffi=3.2
    - healpy -&gt; python=3.5 -&gt; openssl=1.0
    - healpy -&gt; python=3.5 -&gt; readline=7
    - python=3.9
  
  UnsatisfiableError: The following specifications were found to be in conflict:
    - _nb_ext_conf -&gt; python=3.5
    - python=3.7
  </code></pre>
  <p>Could I get 3.9 to work by doing <code>conda remove pymc</code> and <code>conda remove healpy</code>?  Will that break anything?  Is there a better way to upgrade conda/anaconda/python?</p>
  <p>Update: I executed <code>conda remove pymc</code> and then tried <code>conda install conda=4.13.0</code> again.  Now I get</p>
  <pre><code>UnsatisfiableError: The following specifications were found to be in conflict:
    - conda=4.13.0 -&gt; python[version='&gt;=3.7,&lt;3.8.0a0'] -&gt; openssl[version='&gt;=1.1.1b,&lt;1.1.2a']
    - python=3.5
  </code></pre>