anchor.diff:    };
   
     nativeBuildInputs = [ coreutils ] ++ stdenv.lib.optional stdenv.isDarwin cctools;
  -
     buildInputs = [ ncurses libiconv libX11 ];
   
  -  /* We patch out a very annoying 'feature' in ./configure, which
  +  enableParallelBuilding = true;
  +
  +  /*
  +  ** We patch out a very annoying 'feature' in ./configure, which
     ** tries to use 'git' to update submodules.
     **
     ** We have to also fix a few occurrences to tools with absolute
  
positive.code:       --replace "/usr/bin/libtool" libtool
    '';
  
    /* Don't use configureFlags, since that just implicitly appends
    ** everything onto a --prefix flag, which ./configure gets very angry
    ** about.
    */
    configurePhase = ''
      ./configure --threads --installprefix=$out --installman=$out/share/man
    '';
  
    enableParallelBuilding = true;
  
    meta = {
      description = "A powerful and incredibly fast R6RS Scheme compiler";
      homepage    = "http://www.scheme.com";
      license     = stdenv.lib.licenses.asl20;
      platforms   = stdenv.lib.platforms.unix;
      maintainers = with stdenv.lib.maintainers; [ thoughtpolice ];
  
negative.code: 
  stdenv.mkDerivation rec {
    name    = "chez-scheme-${version}";
    version = "9.5.1";
  
    src = fetchgit {
      url    = "https://github.com/cisco/chezscheme.git";
  