anchor.diff:  {stdenv, fetchurl, unicode ? true}:
   
  -stdenv.mkDerivation {
  -  name = "ncurses-5.6";
  +stdenv.mkDerivation rec {
  +  name = "ncurses-5.7";
     
     src = fetchurl {
  -    url = mirror://gnu/ncurses/ncurses-5.6.tar.gz;
  -    md5 = "b6593abe1089d6aab1551c105c9300e3";
  +    url = "mirror://gnu/ncurses/${name}.tar.gz";
  +    sha256 = "1x4q6kma6zgg438llbgiac3kik7j2lln9v97jdffv3fyqyjxx6qa";
     };
     
     configureFlags =
  
positive.code:     " --without-debug";
      
    preBuild = ''sed -e "s@\([[:space:]]\)sh @\1''${SHELL} @" -i */Makefile Makefile'';
  
    # When building a wide-character (Unicode) build, create backward
    # compatibility links from the the "normal" libraries to the
  
negative.code:       fi
      done;
    " else "";
  
    meta = {
      description = "GNU Ncurses, a free software emulation of curses in SVR4 and more";
  
      longDescription = ''
        The Ncurses (new curses) library is a free software emulation of
        curses in System V Release 4.0, and more.  It uses Terminfo
        format, supports pads and color and multiple highlights and
        forms characters and function-key mapping, and has all the other
        SYSV-curses enhancements over BSD Curses.
  
        The ncurses code was developed under GNU/Linux.  It has been in
        use for some time with OpenBSD as the system curses library, and
        on FreeBSD and NetBSD as an external package.  It should port
        easily to any ANSI/POSIX-conforming UNIX.  It has even been
        ported to OS/2 Warp!
      '';
  
      homepage = http://www.gnu.org/software/ncurses/;
  
      license = "X11";
    };
  }
  