$ git clone -n https://src.fedoraproject.org/rpms/xephem.git /var/lib/mock/f45-build-38726-727/root/chroot_tmpdir/scmroot/xephem
Cloning into '/var/lib/mock/f45-build-38726-727/root/chroot_tmpdir/scmroot/xephem'...
$ git fetch origin 3338eb3ab7a226a9b7c6883a2441d0463d814df6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xephem
 * [new ref]         3338eb3ab7a226a9b7c6883a2441d0463d814df6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3338eb3 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild