gentoo-overlay/app-text/qpdfview/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='fitz'>
      Use experimental fitz rendering, provided by <pkg>app-text/mupdf</pkg>,
      instead of poppler
    </flag>
    <flag name='synctex'>Add support for searching TeX sources</flag>
  </use>
</pkgmetadata>