$ git clone -n https://src.fedoraproject.org/rpms/perl-Cookie-Baker.git /var/lib/mock/f40-build-2248250-53944/root/chroot_tmpdir/scmroot/perl-Cookie-Baker
Cloning into '/var/lib/mock/f40-build-2248250-53944/root/chroot_tmpdir/scmroot/perl-Cookie-Baker'...
$ git fetch origin 20de7a30d34da5af9cd32baaf6c41ae08c3ef686:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Cookie-Baker
 * [new ref]         20de7a30d34da5af9cd32baaf6c41ae08c3ef686 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 20de7a3 Upstream update.