$ git clone -n https://src.fedoraproject.org/rpms/libvirt.git /var/lib/mock/f40-build-2433843-60721/root/chroot_tmpdir/scmroot/libvirt
Cloning into '/var/lib/mock/f40-build-2433843-60721/root/chroot_tmpdir/scmroot/libvirt'...
$ git fetch origin b0dd0117281dd01d26aafb52362984c6e240d212:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libvirt
 * [new ref]         b0dd0117281dd01d26aafb52362984c6e240d212 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b0dd011 spec: Handle bash-completion .pc file move