title: conda-forge PackagesNotFoundError for pygraphviz
body: <p>I am trying to install <code>pygraphviz</code> but conda is not finding it in the channels. Below is the error I get. <code>Conda-forge</code> is already in the channel list and I tried with <code>-c conda-forge</code> but still does not work. I also tried <code>bioconda</code> channel and did not work.</p>
  
  <pre><code>&gt; conda install -c anaconda pygraphviz
  Collecting package metadata (current_repodata.json): done
  Solving environment: failed with initial frozen solve. Retrying with flexible solve.
  Collecting package metadata (repodata.json): done
  Solving environment: failed with initial frozen solve. Retrying with flexible solve.
  
  PackagesNotFoundError: The following packages are not available from current channels:
  
    - pygraphviz
  
  Current channels:
  
    - https://conda.anaconda.org/anaconda/win-64
    - https://conda.anaconda.org/anaconda/noarch
    - https://repo.anaconda.com/pkgs/main/win-64
    - https://repo.anaconda.com/pkgs/main/noarch
    - https://repo.anaconda.com/pkgs/r/win-64
    - https://repo.anaconda.com/pkgs/r/noarch
    - https://repo.anaconda.com/pkgs/msys2/win-64
    - https://repo.anaconda.com/pkgs/msys2/noarch
    - https://conda.anaconda.org/conda-forge/win-64
    - https://conda.anaconda.org/conda-forge/noarch
  
  To search for alternate channels that may provide the conda package you're
  looking for, navigate to
  
      https://anaconda.org
  
  and use the search bar at the top of the page.
  </code></pre>
  
  <p><code>Pygraphviz</code> should be there in <a href="https://anaconda.org/bioconda/pygraphviz" rel="nofollow noreferrer">bioconda</a> and <a href="https://anaconda.org/conda-forge/pygraphviz" rel="nofollow noreferrer">conda-forge</a> according to the documentation, but I still cannot find the package. 
  I also update conda <code>conda update conda</code>, and still no luck. </p>
  
  <p>Is there something wrong here? or something I am missing?</p>