gentoo-overlay/media-libs/waffle/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="project">
    <email>x11@gentoo.org</email>
    <name>X11</name>
  </maintainer>
  <use>
    <flag name="wayland">Enable Wayland support</flag>
  </use>
  <upstream>
    <remote-id type="freedesktop-gitlab">mesa/waffle</remote-id>
  </upstream>
</pkgmetadata>