nix-shell environment for running veloren

shell.nix

let
  moz_overlay = import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz);
  nixpkgs = import <nixpkgs> { overlays = [ moz_overlay ]; };
in
  with nixpkgs;
  stdenv.mkDerivation {
    name = "veloren-env";
    buildInputs = [
      (nixpkgs.rustChannelOf { date = "2019-04-11"; channel = "nightly"; }).rust
      git
      pkgconfig
      openssl
      gcc
      libstdcxx5
      libGL
      xorg.libX11 xorg.libXcursor xorg.libXrandr xorg.libXi
      ];
    shellHook = ''
      export RUST_BACKTRACE=1
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${xorg.libX11}/lib
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${xorg.libXcursor}/lib
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${xorg.libXrandr}/lib
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${xorg.libXi}/lib
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${libGL}/lib
    '';
  }

in shellHook, it should be xorg.libX11.out, because it default point to xorg.libX11.bin.