Comment out what you have in your sources file and add the lines below.
( /etc/sysconfig/rhn/sources )
yum development
http://download.fedora.redhat.com/pub/fedora/linux/core/development/$ARCH/
yum-mirror development
http://fedora.redhat.com/download/up2date-mirrors/fedora-core-rawhide
You can then use yum to grab the files needed.
Alan