$ git clone -n https://src.fedoraproject.org/rpms/mathex.git /var/lib/mock/f45-build-18104-508/root/chroot_tmpdir/scmroot/mathex
Cloning into '/var/lib/mock/f45-build-18104-508/root/chroot_tmpdir/scmroot/mathex'...
$ git fetch origin 48bdf028ea367e12cf6a1e89f085a85dd50597c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mathex
 * [new ref]         48bdf028ea367e12cf6a1e89f085a85dd50597c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 48bdf02 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild