$ git clone -n https://src.fedoraproject.org/rpms/erlang-merge_index.git /var/lib/mock/f45-build-8375-386/root/chroot_tmpdir/scmroot/erlang-merge_index
Cloning into '/var/lib/mock/f45-build-8375-386/root/chroot_tmpdir/scmroot/erlang-merge_index'...
$ git fetch origin 8f94dedacc3022386c321e7e35e59c084811da0d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-merge_index
 * [new ref]         8f94dedacc3022386c321e7e35e59c084811da0d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8f94ded Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild