title: Issue with pip install
body: <p>I am trying to install matplotlib with pip, but I get this error:</p>
  
  <p><a href="https://i.stack.imgur.com/ERuNn.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ERuNn.png" alt="enter image description here"></a></p>
  
  <p>Is this an issue with my proxy server?</p>