anchor.diff: -{ lib, stdenv, fetchurl, pkg-config, intltool, itstool, libxml2, gtk3, openssl, gnome3, gobject-introspection, vala, libgee
  -, overrideCC, gcc6, fetchpatch, autoreconfHook, gtk-doc, autoconf-archive, yelp-tools
  -, mysqlSupport ? false, libmysqlclient ? null
  -, postgresSupport ? false, postgresql ? null
  +{ lib
  +, stdenv
  +, fetchurl
  +, pkg-config
  +, intltool
  +, itstool
  +, libxml2
  +, gtk3
  +, openssl
  +, gnome3
  +, gobject-introspection
  +, vala
  +, libgee
  +, overrideCC
  +, gcc6
  +, fetchpatch
  +, autoreconfHook
  +, gtk-doc
  +, autoconf-archive
  +, yelp-tools
  +, mysqlSupport ? false
  +, libmysqlclient ? null
  +, postgresSupport ? false
  +, postgresql ? null
   }:
   
   assert mysqlSupport -> libmysqlclient != null;
  
positive.code: 
    hardeningDisable = [ "format" ];
  
    nativeBuildInputs = [ pkg-config intltool itstool libxml2 gobject-introspection vala autoreconfHook gtk-doc autoconf-archive yelp-tools ];
    buildInputs = with lib; [ gtk3 openssl libgee ]
      ++ optional (mysqlSupport) libmysqlclient
      ++ optional (postgresSupport) postgresql;
  
    passthru = {
      updateScript = gnome3.updateScript {
        packageName = pname;
  
negative.code:   meta = with lib; {
      description = "Database access library";
      homepage = "https://www.gnome-db.org/";
      license = with licenses; [
        # library
        lgpl2Plus
        # CLI tools
        gpl2Plus
      ];
      maintainers = teams.gnome.members;
      platforms = platforms.unix;
    };
  }
  