anchor.diff:  
     meta = with stdenv.lib; {
       description = "Neovim client library and GUI, in Qt5";
  -    license = licenses.isc;
  +    license     = licenses.isc;
       maintainers = with maintainers; [ peterhoeg ];
       inherit (neovim.meta) platforms;
       inherit version;
  
positive.code:   preConfigure = ''
      # avoid cmake trying to download libmsgpack
      echo "" > third-party/CMakeLists.txt
      # we rip out the gui test as spawning a GUI fails in our build environment
      sed -i '/^add_xtest_gui/d' test/CMakeLists.txt
    '';
  
    postInstall = ''
      wrapProgram "$out/bin/nvim-qt" \
  
negative.code: 
  stdenv.mkDerivation rec {
    name = "neovim-qt-${version}";
    version = "0.2.8";
  
    src = fetchFromGitHub {
      owner  = "equalsraf";
      repo   = "neovim-qt";
      rev    = "v${version}";
      sha256 = "190yg6kkw953h8wajlqr2hvs2fz65y6z0blmywlg1nff724allaq";
    };
  
    cmakeFlags = [
      "-DMSGPACK_INCLUDE_DIRS=${libmsgpack}/include"
      "-DMSGPACK_LIBRARIES=${libmsgpack}/lib/libmsgpackc.so"
    ];
  
    buildInputs = with pythonPackages; [
      neovim qtbase libmsgpack
  