$ git clone -n https://src.fedoraproject.org/rpms/rust-arrayref.git /var/lib/mock/f45-build-40130-768/root/chroot_tmpdir/scmroot/rust-arrayref
Cloning into '/var/lib/mock/f45-build-40130-768/root/chroot_tmpdir/scmroot/rust-arrayref'...
$ git fetch origin 998fe4a5a525eb0576c3c3030d489c049dacfe78:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-arrayref
 * [new ref]         998fe4a5a525eb0576c3c3030d489c049dacfe78 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 998fe4a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild