anchor.diff:  , gnugrep, txt2man, makeWrapper, which
   }:
   
  -stdenv.mkDerivation {
  +let
  +  pythonEnv = python.withPackages (ps: [ps.cryptography] );
  +in stdenv.mkDerivation {
     name = "duply-1.9.2";
   
     src = fetchurl {
  
positive.code:   };
  
    buildInputs = [ txt2man makeWrapper ];
  
    phases = [ "unpackPhase" "installPhase" ];
  
    installPhase = ''
  
negative.code:     sed -i 's|/usr/bin/env bash|${bash}/bin/bash|' duply
      mv duply "$out/bin"
      wrapProgram "$out/bin/duply" --set PATH \
          "${coreutils}/bin:${pythonEnv}/bin:${duplicity}/bin:${gawk}/bin:${gnupg1}/bin:${bash}/bin:${gnugrep}/bin:${txt2man}/bin:${which}/bin"
      "$out/bin/duply" txt2man | gzip -c > "$out/share/man/man1/duply.1.gz"
    '';
  
  