anchor.diff:  
   mkDerivation rec {
     pname = "meshlab";
  -  version = "2020.07";
  +  version = "2020.12";
   
     src = fetchFromGitHub {
       owner = "cnr-isti-vclab";
       repo = "meshlab";
       rev = "Meshlab-${version}";
  -    sha256 = "0vj849b57zk3k6lx35zzcjhr9gdy4hxqnnkb8chwy7hw262cm3ri";
  +    sha256 = "QrnqXEVqI1ADUYWalZ0h/0+xS+gDZTinm0weT39onw0=";
       fetchSubmodules = true; # for vcglib
     };
   
  
positive.code: { mkDerivation
  , lib
  , fetchFromGitHub
  , fetchpatch
  , libGLU
  , qtbase
  , qtscript
  
negative.code: 
    postFixup = ''
      patchelf --add-needed $out/lib/meshlab/libmeshlab-common.so $out/bin/.meshlab-wrapped
    '';
  
    meta = {
      description = "A system for processing and editing 3D triangular meshes";
      homepage = "https://www.meshlab.net/";
      license = lib.licenses.gpl3Only;
      maintainers = with lib.maintainers; [ viric ];
      platforms = with lib.platforms; linux;
    };
  