$ git clone -n https://src.fedoraproject.org/rpms/rig.git /var/lib/mock/f40-build-2204969-51976/root/chroot_tmpdir/scmroot/rig
Cloning into '/var/lib/mock/f40-build-2204969-51976/root/chroot_tmpdir/scmroot/rig'...
$ git fetch origin 8b135e902de0bcb422513b57987d425ea2d6498a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rig
 * [new ref]         8b135e902de0bcb422513b57987d425ea2d6498a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8b135e9 Update rig.spec