dotfiles/.config/fontconfig/conf.avail/65-droid-sans-fallback.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
	<alias>
		<family>sans-serif</family>
		<prefer>
			<family>Droid Sans Fallback</family>
		</prefer>
	</alias>
</fontconfig>