anchor.diff:  { lib
   , stdenv
  -, fetchurl
  +, fetchFromGitHub
   , guile
   , pkg-config
   , texinfo
  
positive.code:   ];
  
    meta = with lib; {
      homepage = "http://www.markwitmer.com/guile-xcb/guile-xcb.html";
      description = "XCB bindings for Guile";
      license = licenses.gpl3Plus;
      maintainers = with maintainers; [ vyp ];
  
negative.code:   pname = "guile-xcb";
    version = "1.3";
  
    src = fetchFromGitHub {
      owner = "mwitmer";
      repo = pname;
      rev = version;
      hash = "sha256-8iaYil2wiqnu9p7Gj93GE5akta1A0zqyApRwHct5RSs=";
    };
  
    nativeBuildInputs = [
  