anchor.diff:  }:
   
   let
  -  inherit (stdenv.lib)
  +  inherit (lib)
       boolEn
       optionals;
  +
  +  version = "7.1.1";
   in
   stdenv.mkDerivation rec {
  -  name = "qpdf-6.0.0";
  +  name = "qpdf-${version}";
   
     src = fetchurl {
  -    url = "mirror://sourceforge/qpdf/${name}.tar.gz";
  -    multihash = "QmYAaPsgvdzYAv3svDDBwaaM2k5JPnkw8ky97T2oNtCi2X";
  -    sha1Url = "mirror://sourceforge/qpdf/${name}.sha1";
  -    sha256 = "a9fdc7e94d38fcd3831f37b6e0fe36492bf79aa6d54f8f66062cf7f9c4155233";
  +    url = "mirror://sourceforge/qpdf/qpdf/${version}/${name}.tar.gz";
  +    #sha512Url = "mirror://sourceforge/qpdf/qpdf/${version}/${name}.sha512";
  +    sha256 = "8a0dbfa000a5c257abbc03721c7be277920fe0fcff08202b61c9c2464eedf2fa";
     };
   
     nativeBuildInputs = [
  
positive.code: { stdenv
  , fetchurl
  , perl
  
  , pcre
  
negative.code: 
    doCheck = false;
  
    meta = with lib; {
      description = "Programs to inspect & manipulate PDF files";
      homepage = http://qpdf.sourceforge.net/;
      license = licenses.artistic2;
  