anchor.diff:      libXinerama
       libXrandr
       libXi
  +    mesa_noglu
     ];
   
     buildInputs = [ makeWrapper ];
  
positive.code: { stdenv, callPackage, fetchurl, makeWrapper
  # Begin libraries
  , alsaLib, libX11, libXcursor, libXinerama, libXrandr, libXi
  # Begin download parameters
  , username ? ""
  , password ? ""
  }:
  
  let
    version = "0.12.20";
  
    fetch = callPackage ./fetch.nix { username = username; password = password; };
    arch = if stdenv.system == "x86_64-linux" then "x64"
  
negative.code:   variants = {
      x64 = {
        url = "https://www.factorio.com/get-download/${version}/alpha/linux64";
        sha256 = "01si5n9hb2h0c5q8k3hr3nphsakp9kki84qyp70dgddwqsn8wfjl";
      };
  
      x32 = {
        url = "https://www.factorio.com/get-download/${version}/alpha/linux32";
        sha256 = "13h013ixyhv4rpvh0jv5jry3mrwv65v57nqn16bjh3hr8ip70lkq";
      };
    };
  in
  