anchor.diff:    SDL_audiolib = fetchurl {
       url = "https://github.com/realnc/SDL_audiolib/archive/aa79660eba4467a44f9dcaecf26b0f0a000abfd7.tar.gz";
       sha256 = "0z4rizncp6gqsy72b3709zc9fr915wgcwnlx1fhhy7mrczsly630";
  -  };
  -
  -  SDL_image = fetchurl {
  -    url = "https://github.com/libsdl-org/SDL_image/archive/refs/tags/release-2.0.5.tar.gz";
  -    sha256 = "1zw3k40kbmwc2w9l8fkzrk8maidapmciw3lgcml86pqs9izzddvn";
     };
   
     simpleini = fetchzip {
  
positive.code:     fmt
      libpng
      (SDL2.override { withStatic = true; })
    ];
  
    installPhase = ''
  
negative.code: { lib
  , stdenv
  , fetchFromGitHub
  , fetchpatch
  , fetchurl
  , fetchzip
  , cmake
  , pkg-config
  , gettext
  , SDL2
  , SDL2_image
  , fmt
  , libpng
  , smpq
  }:
  
  let
    # TODO: submit a PR upstream to allow system copies of these libraries where possible
    asio = fetchurl {
      url = "https://github.com/diasurgical/asio/archive/ebeff99f539da23d27c2e8d4bdbc1ee011968644.tar.gz";
      sha256 = "0vhb4cig40mm0a98i74grpmfkcmby8zxg6vqa38dpryxpgvp5fw8";
  