anchor.diff:  
       src = fetchurl {
         url = "mirror://sourceforge/flightgear/release-${shortVersion}/FlightGear-${version}-data.txz";
  -      sha256 = "sha256-/KFumHRkmRvsU/L1i11jG/KbqobnOEP7l4lyPMKHycA=";
  +      sha256 = "sha256-Ej8VGywPQiDw3VXodcpXpOw4qU9x+MBMWMrqwHfitVg=";
       };
   
       dontUnpack = true;
  
positive.code: 
    src = fetchurl {
      url = "mirror://sourceforge/flightgear/release-${shortVersion}/${pname}-${version}.tar.bz2";
      sha256 = "XXDqhZ9nR+FwQ3LauZe8iGxOjlyDXDrEtj61BQGVDYc=";
    };
  
    # Of all the files in the source and data archives, there doesn't seem to be
  
negative.code: }:
  
  let
    version = "2020.3.11";
    shortVersion = builtins.substring 0 6 version;
    data = stdenv.mkDerivation rec {
      pname = "flightgear-data";
  