$ git clone -n https://src.fedoraproject.org/rpms/rubygem-zoom.git /var/lib/mock/f45-build-35405-695/root/chroot_tmpdir/scmroot/rubygem-zoom
Cloning into '/var/lib/mock/f45-build-35405-695/root/chroot_tmpdir/scmroot/rubygem-zoom'...
$ git fetch origin bf286d2d17f765c665a78e53058ecb2d483d7bbb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-zoom
 * [new ref]         bf286d2d17f765c665a78e53058ecb2d483d7bbb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf286d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild