title: Initialize Mercurial for a project in IntelliJ
body: <p>How does one start using Mercurial with an IntelliJ 2017 project?</p>
  <p>➠ Am I expected to manually run a <code>hg init</code> myself, outside of IntelliJ?</p>
  <p><a href="https://stackoverflow.com/a/4282325/642706">This Answer to a similar Question</a> suggests “Yes”, but is several years old.</p>
  <hr />
  <p>When I go to IntelliJ &gt; <code>Settings</code>/<code>Preferences</code> &gt; <code>Version Control</code> and set the only item in the list to a value of <code>Mercurial</code> in the <code>VCS</code> column, and press <code>Apply</code> button, I get this error message:</p>
  <blockquote>
  <p>Invalid VCS root mapping</p>
  <p>The directory  is registered as a hg4idea root, but no hg4idea repositories were found there.</p>
  </blockquote>