$ git clone -n https://src.fedoraproject.org/rpms/mpark-variant.git /var/lib/mock/f45-build-19186-543/root/chroot_tmpdir/scmroot/mpark-variant
Cloning into '/var/lib/mock/f45-build-19186-543/root/chroot_tmpdir/scmroot/mpark-variant'...
$ git fetch origin 9539f7bd857bbd3d293f1dfdbc215f81a8dd2102:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mpark-variant
 * [new ref]         9539f7bd857bbd3d293f1dfdbc215f81a8dd2102 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9539f7b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild