$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell-rpm-generators.git /var/lib/mock/f45-build-11549-432/root/chroot_tmpdir/scmroot/gnome-shell-rpm-generators
Cloning into '/var/lib/mock/f45-build-11549-432/root/chroot_tmpdir/scmroot/gnome-shell-rpm-generators'...
$ git fetch origin abbf078c753716763fd9e9334e727a47cb1bebb4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell-rpm-generators
 * [new ref]         abbf078c753716763fd9e9334e727a47cb1bebb4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at abbf078 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild