$ git clone -n https://src.fedoraproject.org/rpms/onboard.git /var/lib/mock/f40-build-2180017-51101/root/chroot_tmpdir/scmroot/onboard
Cloning into '/var/lib/mock/f40-build-2180017-51101/root/chroot_tmpdir/scmroot/onboard'...
$ git fetch origin a9ac746af5dff7761d183e5e0b12da1c04433a9a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/onboard
 * [new ref]         a9ac746af5dff7761d183e5e0b12da1c04433a9a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a9ac746 Orphaned for 6+ weeks