$ git clone -n https://src.fedoraproject.org/rpms/libixion.git /var/lib/mock/f39-build-1716898-41229/root/chroot_tmpdir/scmroot/libixion
Cloning into '/var/lib/mock/f39-build-1716898-41229/root/chroot_tmpdir/scmroot/libixion'...
$ git fetch origin 39c65eec82abc1349b42354f992a928628ff3772:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libixion
 * [new ref]         39c65eec82abc1349b42354f992a928628ff3772 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39c65ee 0.18