nix-envのバイナリキャッシュを無効にする方法は？

nix-serve/nix バイナリキャッシュを調べようとしています。

ある時点で、私は次のように付け加えました。

  nix = {
    binaryCaches = [
      "https://cache.nixos.org/"
      "http://127.0.0.1:8899"
    ];
    binaryCachePublicKeys = [
      "my-nix-cache:z3o8Kf/PTzehVpMsE2KoYyf5rkU/XCR0+AfEvtKSgo8="
    ];
    trustedUsers = [ "root" "chris" ];
  };

127.0.0.1その後、+ranエントリを削除しましたnixos-rebuild switch。

ところで、使用しようとするたびにまだバイナリキャッシュnix-envとして使用しようとしていますが...127.0.0.1:8899

どのように削除/無効にできますか？

nix-env -i i3     
warning: name collision in input Nix expressions, skipping '/home/chris/.nix-defexpr/channels_root/nixos'
warning: name collision in input Nix expressions, skipping '/home/chris/.nix-defexpr/channels_root/unstable'
installing 'i3-4.16.1'
warning: unable to download 'http://127.0.0.1:8899/09v6jr8gr9g50fm71yamspisi01g9b2d.narinfo': Couldn't connect to server (7); retrying in 324 ms
warning: unable to download 'http://127.0.0.1:8899/fnak72l1m3bci5qfn5719h1jzw2wjsdz.narinfo': Couldn't connect to server (7); retrying in 303 ms
warning: unable to download 'http://127.0.0.1:8899/fnak72l1m3bci5qfn5719h1jzw2wjsdz.narinfo': Couldn't connect to server (7); retrying in 520 ms
warning: unable to download 'http://127.0.0.1:8899/09v6jr8gr9g50fm71yamspisi01g9b2d.narinfo': Couldn't connect to server (7); retrying in 621 ms
warning: unable to download 'http://127.0.0.1:8899/fnak72l1m3bci5qfn5719h1jzw2wjsdz.narinfo': Couldn't connect to server (7); retrying in 1346 ms
warning: unable to download 'http://127.0.0.1:8899/09v6jr8gr9g50fm71yamspisi01g9b2d.narinfo': Couldn't connect to server (7); retrying in 1046 ms
warning: unable to download 'http://127.0.0.1:8899/09v6jr8gr9g50fm71yamspisi01g9b2d.narinfo': Couldn't connect to server (7); retrying in 2506 ms
warning: unable to download 'http://127.0.0.1:8899/fnak72l1m3bci5qfn5719h1jzw2wjsdz.narinfo': Couldn't connect to server (7); retrying in 2528 ms