anchor.diff:  { lib, fetchPypi, buildPythonPackage, python, pkg-config, libX11
  -, SDL, SDL_image, SDL_mixer, SDL_ttf, libpng, libjpeg, portmidi, freetype
  +, SDL2, SDL2_image, SDL2_mixer, SDL2_ttf, libpng, libjpeg, portmidi, freetype
   }:
   
   buildPythonPackage rec {
  
positive.code:   };
  
    nativeBuildInputs = [
      pkg-config SDL
    ];
  
    buildInputs = [
      SDL SDL_image SDL_mixer SDL_ttf libpng libjpeg
      portmidi libX11 freetype
    ];
  
  
negative.code:     sed \
        -e "s/origincdirs = .*/origincdirs = []/" \
        -e "s/origlibdirs = .*/origlibdirs = []/" \
        -e "/linux-gnu/d" \
        -i buildconfig/config_unix.py
      ${lib.concatMapStrings (dep: ''
        sed \
  