anchor.diff:    '';
   
     passthru = {
  -    inherit zlibSupport;
  +    zlibSupport = zlib != null;
       sqliteSupport = sqlite != null;
       db4Support = db4 != null;
       readlineSupport = readline != null;
  
positive.code:     platforms = stdenv.lib.platforms.all;
      maintainers = [ stdenv.lib.maintainers.simons ];
    };
  } // (if stdenv.isDarwin then { NIX_CFLAGS_COMPILE = "-msse2" ; patches = [./search-path.patch]; } else {} ) )
  
negative.code:     sha256 = "1jsqapgwrcqcaskyi2qdn1xj7l8x5340a137hdfshk5ya4dg9xkp";
    };
  
    inherit buildInputs;
    patches = [ ./search-path.patch ];
  
    C_INCLUDE_PATH = concatStringsSep ":" (map (p: "${p}/include") buildInputs);
    LIBRARY_PATH = concatStringsSep ":" (map (p: "${p}/lib") buildInputs);
    configureFlags = "--enable-shared --with-threads --enable-unicode --with-wctype-functions";
  
    preConfigure = ''
      for i in /usr /sw /opt /pkg; do	# improve purity
        substituteInPlace ./setup.py --replace $i /no-such-path
      done
      ${optionalString (ncurses != null) ''export NIX_LDFLAGS="$NIX_LDFLAGS -lncurses"''}
      ${optionalString stdenv.isDarwin   ''export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -msse2"''}
    '';
  
    setupHook = ./setup-hook.sh;
  
  