gentoo-overlay/app-emulation/emul-linux-x86-qtlibs/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>amd64</herd>
<use>
	<flag name="development">Install pkgconfig files</flag>
	<flag name="gtkstyle">Build a Qt style called GTK+ that mimics the
	activeGTK+ theme</flag>
</use>
</pkgmetadata>