gentoo-overlay/dev-java/javacup/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<herd>java</herd>
	<use>
		<flag name="system-jflex">
			Build against system <pkg>dev-java/jflex</pkg> rather than the bundled one.
			Disabling this flag allows breaking the circular dependency when necessary.
		</flag>
	</use>
</pkgmetadata>