$ git clone -n https://src.fedoraproject.org/rpms/ocaml-yojson.git /var/lib/mock/f45-build-20779-573/root/chroot_tmpdir/scmroot/ocaml-yojson
Cloning into '/var/lib/mock/f45-build-20779-573/root/chroot_tmpdir/scmroot/ocaml-yojson'...
$ git fetch origin fa6853a953752ba328e403c11ce1661803a8d80e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-yojson
 * [new ref]         fa6853a953752ba328e403c11ce1661803a8d80e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fa6853a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild