$ git clone -n https://src.fedoraproject.org/rpms/erlang-chronos.git /var/lib/mock/f41-build-side-1-2811237-32927/root/chroot_tmpdir/scmroot/erlang-chronos
Cloning into '/var/lib/mock/f41-build-side-1-2811237-32927/root/chroot_tmpdir/scmroot/erlang-chronos'...
$ git fetch origin 84e53c89ed9656ddcfb720a977209cbeed0889b4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-chronos
 * [new ref]         84e53c89ed9656ddcfb720a977209cbeed0889b4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 84e53c8 Cosmetic changes