anchor.diff:      #   https://github.com/NixOS/nixpkgs/pull/63174
       #   https://github.com/NixOS/nixpkgs/pull/72342
       ./utf8-xmlErrorFuncHandler.patch
  -    (fetchpatch {
  -      name = "CVE-2019-20388.patch";
  -      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/6088a74bcf7d0c42e24cff4594d804e1d3c9fbca.patch";
  -      sha256 = "070s7al2r2k92320h9cdfc2097jy4kk04d0disc98ddc165r80jl";
  -    })
  -    (fetchpatch {
  -      name = "CVE-2020-7595.patch";
  -      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5.patch";
  -      sha256 = "0klvaxkzakkpyq0m44l9xrpn5kwaii194sqsivfm6zhnb9hhl15l";
  -    })
  -    (fetchpatch {
  -      name = "CVE-2020-24977.patch";
  -      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2.patch";
  -      sha256 = "093f1ic5qfiq8nk9mc6b8p1qcs8m9hir3ardr6r5il4zi2dnjrj4";
  -    })
  -    # Fix compatibility with Python 3.9.
  -    # https://gitlab.gnome.org/GNOME/libxml2/-/issues/149
  -    (fetchpatch {
  -      name = "python39.patch";
  -      url = "https://gitlab.gnome.org/nwellnhof/libxml2/-/commit/e4fb36841800038c289997432ca547c9bfef9db1.patch";
  -      sha256 = "0h3vpy9fg3339b14qa64640ypp65z3hrrrmpjl8qm72srkp24ci5";
  -    })
     ];
   
     outputs = [ "bin" "dev" "out" "man" "doc" ]
  
positive.code: { stdenv, lib, fetchurl, fetchpatch
  , zlib, xz, libintl, python, gettext, ncurses, findXMLCatalogs
  , pythonSupport ? enableShared && stdenv.buildPlatform == stdenv.hostPlatform
  , icuSupport ? false, icu ? null
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "libxml2";
    version = "2.9.12";
  
    src = fetchurl {
      url = "http://xmlsoft.org/sources/${pname}-${version}.tar.gz";
      sha256 = "14hxwzmf5xqppx77z7i0ni9lpzg1a84dqpf8j8l1fvy570g6imn8";
    };
    patches = [
      # Upstream bugs:
  