$ git clone -n https://src.fedoraproject.org/rpms/perl-Gtk2-Ex-Utils.git /var/lib/mock/f45-build-23836-599/root/chroot_tmpdir/scmroot/perl-Gtk2-Ex-Utils
Cloning into '/var/lib/mock/f45-build-23836-599/root/chroot_tmpdir/scmroot/perl-Gtk2-Ex-Utils'...
$ git fetch origin 6478e614fce7a7de839a1824647fc7e806655f62:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Gtk2-Ex-Utils
 * [new ref]         6478e614fce7a7de839a1824647fc7e806655f62 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6478e61 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild