anchor.diff:    preConfigure = ''
       export BORG_OPENSSL_PREFIX="${openssl}"
       export BORG_LZ4_PREFIX="${lz4}"
  -    # note: fix for this issue already upstream and probably in 0.27.1 (or whatever the next release is called)
  -    substituteInPlace setup.py --replace "possible_openssl_prefixes.insert(0, os.environ.get('BORG_LZ4_PREFIX'))" "possible_lz4_prefixes.insert(0, os.environ.get('BORG_LZ4_PREFIX'))"
     '';
   
     meta = with stdenv.lib; {
  
positive.code:     homepage = https://borgbackup.github.io/;
      license = licenses.bsd3;
      platforms = platforms.unix; # Darwin and FreeBSD mentioned on homepage
    };
  }
  
negative.code: 
  python3Packages.buildPythonPackage rec {
    name = "borgbackup-${version}";
    version = "0.29.0";
    namePrefix = "";
  
    src = fetchurl {
      url = "https://pypi.python.org/packages/source/b/borgbackup/borgbackup-${version}.tar.gz";
      sha256 = "1gvx036a7j16hd5rg8cr3ibiig7gwqhmddrilsakcw4wnfimjy5m";
    };
  
    propagatedBuildInputs = with python3Packages;
  