anchor.diff:        - history mechanism
         - job control
       '';
  -    homepage = "https://www.tcsh.org/";
       license = licenses.bsd2;
       maintainers = with maintainers; [ AndersonTorres ];
  -    platforms = platforms.linux ++ platforms.darwin;
  +    platforms = platforms.unix;
     };
   
     passthru = {
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "tcsh";
    version = "6.22.03";
  
    src = fetchurl {
      urls = [
  
negative.code:       "ftp://ftp.funet.fi/pub/unix/shells/tcsh/${pname}-${version}.tar.gz"
        "ftp://ftp.funet.fi/pub/unix/shells/tcsh/old/${pname}-${version}.tar.gz"
      ];
      hash = "sha256-6xY1YkMhjDLzngcljXK/iyHmLOlLsOipXjGLFROX4jE=";
    };
  
    buildInputs = [ ncurses ];
  