$ git clone -n https://src.fedoraproject.org/rpms/perl-Email-Stuffer.git /var/lib/mock/f45-build-23311-596/root/chroot_tmpdir/scmroot/perl-Email-Stuffer
Cloning into '/var/lib/mock/f45-build-23311-596/root/chroot_tmpdir/scmroot/perl-Email-Stuffer'...
$ git fetch origin 4cb69b011888bba8fdfad13410b32d91ef15255e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Email-Stuffer
 * [new ref]         4cb69b011888bba8fdfad13410b32d91ef15255e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4cb69b0 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild