title: Installing pygrahviz in google colab
body: <p>In order to install graphviz, one can follow, this example: 
  <a href="https://colab.research.google.com/drive/1_Qb92Hj5_f2rpta67JC0JKXwE2581Ar-#scrollTo=BOa9gIcDo6GS" rel="noreferrer">https://colab.research.google.com/drive/1_Qb92Hj5_f2rpta67JC0JKXwE2581Ar-#scrollTo=BOa9gIcDo6GS</a></p>
  
  <p>When I try to install pygraphviz (<a href="https://pygraphviz.github.io/" rel="noreferrer">https://pygraphviz.github.io/</a>) via (<a href="https://pypi.org/project/pygraphviz/" rel="noreferrer">https://pypi.org/project/pygraphviz/</a>)</p>
  
  <p>with </p>
  
  <pre><code>!pip install pygraphviz
  import pygraphviz as pgv
  </code></pre>
  
  <p>i get the error </p>
  
  <pre><code>ERROR: Failed building wheel for pygraphviz
  </code></pre>
  
  <p>although I installed graphviz before.
  Why?</p>