anchor.diff:      pkg-config
       gobject-introspection
       vala
  -    gtk-doc
  -    docbook_xsl
  -    docbook_xml_dtd_412
  +    gi-docgen
  +    python3
     ];
   
     buildInputs = [
       libsoup
  -    gtk3
     ];
   
     propagatedBuildInputs = [
  
positive.code:     description = "GObject-based API for handling resource discovery and announcement over SSDP";
      homepage = "http://www.gupnp.org/";
      license = licenses.lgpl2Plus;
      platforms = platforms.all;
    };
  }
  
negative.code: 
    mesonFlags = [
      "-Dgtk_doc=true"
      "-Dsniffer=false"
    ];
  
    doCheck = true;
  
    postFixup = ''
      # Cannot be in postInstall, otherwise _multioutDocs hook in preFixup will move right back.
      find -L "$out/share/doc" -type f -regex '.*\.devhelp2?' -print0 \
        | while IFS= read -r -d ''' file; do
          moveToOutput "$(dirname "''${file/"$out/"/}")" "$devdoc"
      done
    '';
  
    passthru = {
      updateScript = gnome.updateScript {
  