$ git clone -n https://src.fedoraproject.org/rpms/libnova.git /var/lib/mock/f45-build-16652-489/root/chroot_tmpdir/scmroot/libnova
Cloning into '/var/lib/mock/f45-build-16652-489/root/chroot_tmpdir/scmroot/libnova'...
$ git fetch origin ca9e02ff897b2a82735b893e3f429757e8c2fe38:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libnova
 * [new ref]         ca9e02ff897b2a82735b893e3f429757e8c2fe38 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca9e02f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild