$ git clone -n https://src.fedoraproject.org/rpms/grass.git /var/lib/mock/f39-build-1872431-42723/root/chroot_tmpdir/scmroot/grass
Cloning into '/var/lib/mock/f39-build-1872431-42723/root/chroot_tmpdir/scmroot/grass'...
$ git fetch origin 4d5fa75ad62a82578cd73cbf26de12cd56043517:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/grass
 * [new ref]         4d5fa75ad62a82578cd73cbf26de12cd56043517 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4d5fa75 fix obsolete configure parameters