dev-ruby/rubygems/metadata.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<herd>ruby</herd>
	<use>
		<flag name="server">Install support for the rubygems server</flag>
	</use>
</pkgmetadata>