anchor.diff: -{ lib, mkDerivation, fetchFromGitHub, fetchpatch
  +{ lib, mkDerivation, fetchFromGitHub
   , python3, ruby, qtbase, qtmultimedia, qttools, qtxmlpatterns
  -, which, perl, makeWrapper
  +, which, perl
   }:
   
   mkDerivation rec {
     pname = "klayout";
  -  version = "0.27.3";
  +  version = "0.27.8";
   
     src = fetchFromGitHub {
       owner = "KLayout";
       repo = "klayout";
       rev = "v${version}";
  -    sha256 = "sha256-6g/QoR16rhUfxhH4JxL6EERcoPVG/6MOxUlo6K/WoE0=";
  +    hash = "sha256-t/nd7m8XpB026q/kyH16rKkw3qza19ISalB0Juzx4NU=";
     };
   
     postPatch = ''
  
positive.code: 
    nativeBuildInputs = [
      which
      python3
      ruby
    ];
  
negative.code:   buildPhase = ''
      runHook preBuild
      mkdir -p $out/lib
      ./build.sh -qt5 -prefix $out/lib -option -j$NIX_BUILD_CORES
      runHook postBuild
    '';
  
  