anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "libmanette";
  -  version = "0.2.5";
  +  version = "0.2.6";
   
  -  outputs = [ "out" "dev" ];
  +  outputs = [ "out" "dev" "devdoc" ];
   
     src = fetchurl {
       url = "mirror://gnome/sources/${pname}/${stdenv.lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
  -    sha256 = "gAbghIDAy9T3SewVWCfRAER88jkD+tgkCnxMMhqgmis=";
  +    sha256 = "1b3bcdkk5xd5asq797cch9id8692grsjxrc1ss87vv11m1ck4rb3";
     };
   
     nativeBuildInputs = [
  
positive.code: , pkgconfig
  , vala
  , gobject-introspection
  , glib
  , libgudev
  , libevdev
  
negative.code:     pkgconfig
      vala
      gobject-introspection
      gtk-doc
      docbook-xsl-nons
      docbook_xml_dtd_43
    ];
  
    buildInputs = [
      glib
      libgudev
      libevdev
    ];
  
    mesonFlags = [
      "-Ddoc=true"
    ];
  
    doCheck = true;
  