$ git clone -n https://src.fedoraproject.org/rpms/gnudos.git /var/lib/mock/f40-build-2196864-51605/root/chroot_tmpdir/scmroot/gnudos
Cloning into '/var/lib/mock/f40-build-2196864-51605/root/chroot_tmpdir/scmroot/gnudos'...
$ git fetch origin 73f919cbe8a701849b62b4098a142f59e117c650:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnudos
 * [new ref]         73f919cbe8a701849b62b4098a142f59e117c650 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 73f919c Orphaned for 6+ weeks