gentoo-overlay/dev-libs/gjs/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="project">
    <email>gnome@gentoo.org</email>
    <name>Gentoo GNOME Desktop</name>
  </maintainer>
  <use>
    <flag name="sysprof">Enable profiling data capture support using <pkg>dev-util/sysprof-capture</pkg></flag>
  </use>
</pkgmetadata>