$ git clone -n https://src.fedoraproject.org/rpms/erlang-gun.git /var/lib/mock/f45-build-8332-384/root/chroot_tmpdir/scmroot/erlang-gun
Cloning into '/var/lib/mock/f45-build-8332-384/root/chroot_tmpdir/scmroot/erlang-gun'...
$ git fetch origin 9213bc7d5f8ed30190e0684d6a1cdbfb9b9250c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-gun
 * [new ref]         9213bc7d5f8ed30190e0684d6a1cdbfb9b9250c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9213bc7 gun ver. 2.5.0