anchor.diff:  
     mesonFlags = [
       "--datadir=${placeholder "dev"}/share"
  -    "-Ddoctool=disabled"
       "-Dcairo=disabled"
       "-Dgtk_doc=${lib.boolToString (stdenv.hostPlatform == stdenv.buildPlatform)}"
     ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
  
positive.code:     gtk-doc
      docbook-xsl-nons
      docbook_xml_dtd_45
      python3
      finalAttrs.setupHook # move .gir files
    ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [ gobject-introspection-unwrapped ];
  
    buildInputs = [
      python3
    ];
  
    checkInputs = lib.optionals stdenv.isDarwin [
  
negative.code: # it may be worth thinking about using multiple derivation outputs
  # In that case its about 6MB which could be separated
  
  let
    pythonModules = pp: [
      pp.Mako
      pp.markdown
    ];
  in
  stdenv.mkDerivation (finalAttrs: {
    pname = "gobject-introspection";
    version = "1.72.0";
  