anchor.diff:    nativeBuildInputs = [
       meson ninja pkgconfig gettext
       libxslt xmlto docbook_xsl docbook_xml_dtd_45
  -    gobjectIntrospection itstool
  +    gobjectIntrospection itstool vala
     ];
   
     buildInputs = [ libstemmer pcre glib xapian libxml2 libyaml ];
  
positive.code:   mesonFlags = [
      "-Dapidocs=false"
      "-Ddocs=false"
    ];
  
    meta = with stdenv.lib; {
  
negative.code: { stdenv, fetchpatch, fetchFromGitHub, meson, ninja, pkgconfig, gettext
  , xmlto, docbook_xsl, docbook_xml_dtd_45, libxslt
  , libstemmer, glib, xapian, libxml2, libyaml, gobjectIntrospection
  , pcre, itstool, vala
  }:
  
  stdenv.mkDerivation rec {
  