$ git clone -n https://src.fedoraproject.org/rpms/rust-nu-json.git /var/lib/mock/f40-build-2642527-66458/root/chroot_tmpdir/scmroot/rust-nu-json
Cloning into '/var/lib/mock/f40-build-2642527-66458/root/chroot_tmpdir/scmroot/rust-nu-json'...
$ git fetch origin 473072d8ebd76d44feb4edbdb0884c51384f7169:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-nu-json
 * [new ref]         473072d8ebd76d44feb4edbdb0884c51384f7169 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 473072d Update to 0.91.0 (rhbz#2257506)