anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "VASSAL";
  -  version = "3.6.4";
  +  version = "3.6.5";
   
     src = fetchzip {
       url = "https://github.com/vassalengine/vassal/releases/download/${version}/${pname}-${version}-linux.tar.bz2";
  -    sha256 = "sha256-WUEpYxzNcH9kJRn4nROoaeXTe1+D4/0VRqTwc7ac1hc=";
  +    sha256 = "sha256-wnaT0+r599/RboeUfpCZTNd/M2kaCsckI9F+7r7leEE=";
     };
   
     nativeBuildInputs = [ makeWrapper ];
   
     installPhase = ''
  +    runHook preInstall
  +
       mkdir -p $out/bin $out/share/vassal $out/doc
   
       cp CHANGES LICENSE README.md $out
  
positive.code:     makeWrapper ${jre}/bin/java $out/bin/vassal \
        --add-flags "-Duser.dir=$out -cp $out/share/vassal/Vengine.jar \
        VASSAL.launch.ModuleManager"
    '';
  
    # Don't move doc to share/, VASSAL expects it to be in the root
  
negative.code: 
    meta = with lib; {
        description = "A free, open-source boardgame engine";
        homepage = "https://vassalengine.org/";
        license = licenses.lgpl21Only;
        maintainers = with maintainers; [ tvestelind ];
        platforms = platforms.unix;
  