$ git clone -n https://src.fedoraproject.org/rpms/rust-nibble_vec.git /var/lib/mock/f45-build-43355-802/root/chroot_tmpdir/scmroot/rust-nibble_vec
Cloning into '/var/lib/mock/f45-build-43355-802/root/chroot_tmpdir/scmroot/rust-nibble_vec'...
$ git fetch origin f29847e38d4ffa785353b89d5d30efa44a835633:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-nibble_vec
 * [new ref]         f29847e38d4ffa785353b89d5d30efa44a835633 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f29847e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild