gentoo-overlay/www-client/qupzilla/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>qt</herd>
  <use>
    <flag name='nonblockdialogs'>Enable fancy non-blocking JavaScript dialogs
      shown inside the page, not blocking the application window. When closing
      browser windows with open dialogs, this can crash the application.
    </flag>
  </use>
</pkgmetadata>