$ git clone -n https://src.fedoraproject.org/rpms/groonga.git /var/lib/mock/f42-build-864574-172456/root/chroot_tmpdir/scmroot/groonga
Cloning into '/var/lib/mock/f42-build-864574-172456/root/chroot_tmpdir/scmroot/groonga'...
$ git fetch origin 07ee2609e53e28aa8090c5e087667c8c37be2960:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/groonga
 * [new ref]         07ee2609e53e28aa8090c5e087667c8c37be2960 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 07ee260 Rebuild for libarrow 18