anchor.diff:  in
   stdenv.mkDerivation rec {
     name = "slic3r-prusa-edition-${version}";
  -  version = "1.39.2";
  +  version = "1.40.0";
   
     enableParallelBuilding = true;
   
     buildInputs = [
       cmake
  +    curl
       perl
       makeWrapper
       eigen
  
positive.code: 
      # it seems we need to copy the icons...
      mkdir -p $out/bin/var
      cp ../resources/icons/* $out/bin/var/
      cp -r ../resources $out/bin/
    '';
  
    src = fetchFromGitHub {
      owner = "prusa3d";
      repo = "Slic3r";
      sha256 = "0vbqkmd2yqi469ijqm4wyzjmq9w1kwiy8av1kchm4429z5hpmxcd";
      rev = "version_${version}";
    };
  
  
negative.code: 
    prePatch = ''
      sed -i 's|"/usr/include/asm-generic/ioctls.h"|<asm-generic/ioctls.h>|g' xs/src/libslic3r/GCodeSender.cpp
      sed -i "s|\''${PERL_VENDORARCH}|$out/lib/slic3r-prusa3d|g" xs/CMakeLists.txt
      sed -i "s|\''${PERL_VENDORLIB}|$out/lib/slic3r-prusa3d|g" xs/CMakeLists.txt
    '';
  
    postInstall = ''
  