gentoo-overlay/media-plugins/gkrellmpc/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<herd>sound</herd>
	<herd>desktop-dock</herd>
	<use>
		<flag name="threads">Use separate thread to init connection (unsafe)</flag>
	</use>
</pkgmetadata>