gentoo-overlay/media-libs/clutter/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="egl">Enable EGL backend.</flag>
	<flag name="gtk">Use gdk-pixbuf from <pkg>x11-libs/gtk+</pkg> as image rendering backend</flag>
</use>
</pkgmetadata>