anchor.diff: -{ lib, stdenv, fetchurl, perl, expat, xlibsWrapper, freetype }:
  +{ lib
  +, stdenv
  +, fetchurl
  +, perl
  +, expat
  +, xlibsWrapper
  +, freetype
  +}:
   
   # !!! assert freetype == xorg.freetype
   
  
positive.code: 
    src = fetchurl {
      url = "https://www.logicalshift.co.uk/unix/zoom/zoom-${version}.tar.gz";
      sha256 = "1g6van7f7sg3zfcz80mncnnbccyg2hnm0hq4x558vpsm0lf7z5pj";
    };
  
    buildInputs = [ perl expat xlibsWrapper freetype ];
  
negative.code:   NIX_CFLAGS_COMPILE = "-I${freetype}/include/freetype2 -fgnu89-inline";
  
    meta = with lib; {
      homepage = "https://www.logicalshift.co.uk/unix/zoom/";
      description = "Player for Z-Code, TADS and HUGO stories or games";
      longDescription = ''
        Zoom is a player for Z-Code, TADS and HUGO stories or games. These are
  