anchor.diff:  { stdenv, fetchurl, tcl, makeWrapper }:
   
  -let version = "5.45";
  -in
  -stdenv.mkDerivation {
  +stdenv.mkDerivation rec {
  +  version = "5.45";
     name = "expect-${version}";
   
     src = fetchurl {
  
positive.code:     for i in $out/bin/*; do
        wrapProgram $i \
          --prefix PATH : "${tcl}/bin" \
          --prefix TCLLIBPATH ' ' $out/lib/*
      done
    '';
  
  
negative.code:     description = "A tool for automating interactive applications";
      homepage = http://expect.nist.gov/;
      license = "Expect";
      platforms = platforms.unix;
      maintainers = with maintainers; [ wkennington ];
    };
  }
  