gentoo-overlay/x11-misc/grsync/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="person">
    <email>voyageur@gentoo.org</email>
    <name>Bernard Cafarelli</name>
  </maintainer>
  <use>
    <flag name="gtk3">Link against <pkg>x11-libs/gtk+</pkg>:3 instead of <pkg>x11-libs/gtk+</pkg>:2</flag>
  </use>
</pkgmetadata>