$ git clone -n https://src.fedoraproject.org/rpms/pairs.git /var/lib/mock/f40-build-2247999-53934/root/chroot_tmpdir/scmroot/pairs
Cloning into '/var/lib/mock/f40-build-2247999-53934/root/chroot_tmpdir/scmroot/pairs'...
$ git fetch origin d42b6ca6a46fbabca8fc022f6d032741f517c8a3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pairs
 * [new ref]         d42b6ca6a46fbabca8fc022f6d032741f517c8a3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d42b6ca Orphaned for 6+ weeks