title: Unknown module(s) in QT: core gui quick
body: <p>I've screwed up another OS, haven't I?</p>
  <p>I installed Pop!_OS 21.04 (based on Ubuntu Hirsute) two days ago, and I'm trying to build a QML app I programmed on FreeBSD. qmake doesn't make the project, complaining that</p>
  <pre><code>error: Project ERROR: Unknown module(s) in QT: core gui quick
  </code></pre>
  <p>I installed Qt Creator through <code>apt</code>.</p>
  <p>KDE works fine, so does LXQt. Flatpak Qt Creator also works.</p>
  <p>The same issue happens on Debian, so I'm assuming it'll happen in every Debian-based OS.</p>