mosh with patched libutempter for nixos

{config, pkgs, lib, ...}:
let
    libutempter = pkgs.libutempter.overrideAttrs ( oldAttrs: {
      prePatch = oldAttrs.prePatch + ''
        substituteInPlace iface.c --replace 'LIBEXECDIR "/utempter/utempter"' '"/run/wrappers/bin/utempter"'
      '';

    } );
    mosh = pkgs.mosh.overrideAttrs ( oldAttrs: {
        buildInputs = oldAttrs.buildInputs ++ [ libutempter ];
        configureFlags = oldAttrs.configureFlags ++ [ "--with-utempter" ];
      } );
in
{
    networking.firewall.allowedUDPPortRanges = [ { from = 60000; to = 61000; } ];

    environment.systemPackages = [
        mosh
    ];

    security.wrappers = {
      utempter = {
          source = "${libutempter}/lib/utempter/utempter";
          program = "utempter";
      };
    };
}