anchor.diff: -{ stdenv, fetchurl, tcl }:
  +{ stdenv, fetchurl, tcl, makeWrapper }:
   
   let version = "5.45";
   in
  
positive.code:   configureFlags = [
      "--with-tcl=${tcl}/lib"
      "--with-tclinclude=${tcl}/include"
      "--exec-prefix=$out"
    ];
  
    postInstall = let libSuff = if stdenv.isDarwin then "dylib" else "so";
      in "cp expect $out/bin; mkdir -p $out/lib; cp *.${libSuff} $out/lib";
  
    meta = {
      description = "A tool for automating interactive applications";
  
negative.code:   };
  
    buildInputs = [ tcl ];
    nativeBuildInputs = [ makeWrapper ];
  
    #NIX_CFLAGS_COMPILE = "-DHAVE_UNISTD_H";
  
  