$ git clone -n https://src.fedoraproject.org/rpms/arpwatch.git /var/lib/mock/f42-build-885730-186912/root/chroot_tmpdir/scmroot/arpwatch
Cloning into '/var/lib/mock/f42-build-885730-186912/root/chroot_tmpdir/scmroot/arpwatch'...
$ git fetch origin aa93d898b1daadd6439195a75481c3343df5bf95:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/arpwatch
 * [new ref]         aa93d898b1daadd6439195a75481c3343df5bf95 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aa93d89 Drop call to %sysusers_create_compat