title: Error installing coincurve with python preinstalled pip3
body: <p>I was trying to install <strong>coincurve</strong> with <code>pip3 install coincurve</code> when this error occurred, help needed please
  <a href="https://i.stack.imgur.com/e29bg.jpg" rel="nofollow noreferrer">Ubuntu console screenshot</a></p>
  <p>Full traceback: <a href="https://pastebin.com/5SBMgNB9" rel="nofollow noreferrer">https://pastebin.com/5SBMgNB9</a></p>