anchor.diff:  assert imagePreviewSupport -> w3m != null;
   
   pythonPackages.buildPythonApplication rec {
  -  name = "ranger-1.8.1";
  +  name = "ranger-v${version}";
  +  version = "1.9.0";
   
  -  meta = {
  -    description = "File manager with minimalistic curses interface";
  -    homepage = http://ranger.nongnu.org/;
  -    license = stdenv.lib.licenses.gpl3;
  -    platforms = stdenv.lib.platforms.unix;
  -  };
  -
  -  src = fetchurl {
  -    url = "http://ranger.nongnu.org/${name}.tar.gz";
  -    sha256 = "1d11qw0mr9aj22a7nhr6p2c3yzf359xbffmjsjblq44bjpwzjcql";
  +  src = fetchFromGitHub {
  +    owner = "ranger";
  +    repo = "ranger";
  +    rev = "v${version}";
  +    sha256= "0h3qz0sr21390xdshhlfisvscja33slv1plzcisg1wrdgwgyr5j6";
     };
   
     checkInputs = with pythonPackages; [ pytest ];
  
positive.code: { stdenv, fetchurl, pythonPackages, file, less
  , imagePreviewSupport ? true, w3m ? null}:
  
  with stdenv.lib;
  
negative.code:       --replace "set preview_images false" "set preview_images true" \
    '';
  
    meta =  with stdenv.lib; {
      description = "File manager with minimalistic curses interface";
      homepage = http://ranger.github.io/;
      license = licenses.gpl3;
      platforms = platforms.unix;
      maintainers = [ maintainers.magnetophon ];
    };
  }
  