anchor.diff:    tclLibraries = stdenv.lib.optionals tkremind [ tcllib tk ];
     tclLibPaths = stdenv.lib.concatStringsSep " "
       (map (p: "${p}/lib/${p.libPrefix}") tclLibraries);
  +  tkremindPatch = optionalString tkremind ''
  +    substituteInPlace scripts/tkremind --replace "exec wish" "exec ${tk}/bin/wish"
  +  '';
   in stdenv.mkDerivation {
     name = "remind-3.1.16";
     src = fetchurl {
  
positive.code:   nativeBuildInputs = optional tkremind makeWrapper;
    propagatedBuildInputs = tclLibraries;
  
    postPatch = optionalString tkremind ''
      substituteInPlace scripts/tkremind --replace "exec wish" "exec ${tk}/bin/wish"
    '';
  
    postInstall = optionalString tkremind ''
  
negative.code:     description = "Sophisticated calendar and alarm program for the console";
      license = stdenv.lib.licenses.gpl2;
      maintainers = with stdenv.lib.maintainers; [raskin kovirobi];
      platforms = with stdenv.lib.platforms; unix;
    };
  }
  