anchor.diff:  { stdenv, fetchFromGitHub, cmake, gettext, libmsgpack, libtermkey
   , libtool, libuv, luajit, luaPackages, man, ncurses, perl, pkgconfig
  -, unibilium, makeWrapper, vimUtils, xsel
  +, unibilium, makeWrapper, vimUtils, xsel, gperf
   
   , withPython ? true, pythonPackages, extraPythonPackages ? []
   , withPython3 ? true, python3Packages, extraPython3Packages ? []
  
positive.code:       unibilium
        luajit
        luaPackages.lua
      ] ++ optional withJemalloc jemalloc
        ++ lualibs;
  
  
negative.code: 
    neovim = stdenv.mkDerivation rec {
      name = "neovim-${version}";
      version = "0.1.6";
  
      src = fetchFromGitHub {
        owner = "neovim";
        repo = "neovim";
        rev = "v${version}";
        sha256 = "0s8vqf4aym1d1h8yi0znpqw5rv9v3z64y5aha9dmynbwxa58q7pp";
      };
  
      enableParallelBuilding = true;
  