$ git clone -n https://src.fedoraproject.org/rpms/fedora-upgrade.git /var/lib/mock/f40-build-1996308-44002/root/chroot_tmpdir/scmroot/fedora-upgrade
Cloning into '/var/lib/mock/f40-build-1996308-44002/root/chroot_tmpdir/scmroot/fedora-upgrade'...
$ git fetch origin e6f28688945fc4e32ae30184278d43b88693d77e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fedora-upgrade
 * [new ref]         e6f28688945fc4e32ae30184278d43b88693d77e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e6f2868 setup packit pull-from-upstream automation