anchor.diff: -{ lib, stdenv
  +{ lib
  +, stdenv
   , gettext
   , fetchurl
   , evolution-data-server
   , pkg-config
   , libxslt
  -, docbook_xsl
  +, docbook-xsl-nons
   , docbook_xml_dtd_42
   , python3
  -, gtk3
  +, gtk4
   , glib
  -, cheese
  -, libchamplain
  -, clutter-gtk
  -, geocode-glib
  +, libportal
   , gnome-desktop
   , gnome-online-accounts
   , wrapGAppsHook
  
positive.code:     vala
      gettext
      libxslt
      docbook_xsl
      docbook_xml_dtd_42
      python3
      wrapGAppsHook
    ];
  
    buildInputs = [
      gtk3
      glib
      evolution-data-server
      gsettings-desktop-schemas
      folks
      gnome-desktop
      libhandy
      libxml2
      gnome-online-accounts
      cheese
      gnome.adwaita-icon-theme
      libchamplain
      clutter-gtk
      geocode-glib
    ];
  
    postPatch = ''
      chmod +x build-aux/meson_post_install.py
      patchShebangs build-aux/meson_post_install.py
    '';
  
    doCheck = true;
  
  
negative.code: , vala
  , meson
  , ninja
  , libadwaita
  , gsettings-desktop-schemas
  }:
  
  stdenv.mkDerivation rec {
    pname = "gnome-contacts";
    version = "42.alpha";
  
    src = fetchurl {
      url = "mirror://gnome/sources/gnome-contacts/${lib.versions.major version}/${pname}-${version}.tar.xz";
      sha256 = "nTMBGn3/FW/zCNwgGiFSE6vV3x7lyZxKnmc4atwoTA8=";
    };
  
    propagatedUserEnvPkgs = [
  