title: Github: How to solve hanging pull request?
body: <p>My <a href="https://github.com/WeeSee/yii2-usuario" rel="nofollow noreferrer">repo</a> is a fork from upstream repo <a href="https://github.com/2amigos/yii2-usuario" rel="nofollow noreferrer">2amigos/yii2-usuario</a>.</p>
  <p>My repo is behind some commits. I want to re-sync all commit and created a pull request by switching the base, so that the upstream repo gets merged into my repo.</p>
  <p>While <a href="https://github.com/WeeSee/yii2-usuario/pull/1" rel="nofollow noreferrer">creating the pull request</a>, Github says</p>
  <pre><code>Able to merge. These branches can be automatically merged.
  </code></pre>
  <p>But, when the pull request is created, Github just <a href="https://github.com/WeeSee/yii2-usuario/pull/1" rel="nofollow noreferrer">shows</a></p>
  <pre><code>Checking for ability to merge automatically…
  Hang in there while we check the branch’s status.
  </code></pre>
  <p>I cannot perform any action, neither kill the pull request nor solve it.
  What should I do?</p>