$ git clone -n https://src.fedoraproject.org/rpms/radvd.git /var/lib/mock/f40-build-2223930-52761/root/chroot_tmpdir/scmroot/radvd
Cloning into '/var/lib/mock/f40-build-2223930-52761/root/chroot_tmpdir/scmroot/radvd'...
$ git fetch origin c77e9d991e93ed8bfacd17ef5b6613d5e7231b6b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/radvd
 * [new ref]         c77e9d991e93ed8bfacd17ef5b6613d5e7231b6b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c77e9d9 Backport upstream patch to fix another C99 issue in configure