anchor.diff:  , fetchFromGitHub
   , flex
   , libffi
  -, pkgconfig
  +, pkg-config
   , protobuf
   , python3
   , readline
  
positive.code:   };
  
    enableParallelBuilding = true;
    nativeBuildInputs = [ pkgconfig ];
    buildInputs = [ tcl readline libffi python3 bison flex protobuf zlib ];
  
    makeFlags = [ "ENABLE_PROTOBUF=1" "PREFIX=${placeholder "out"}"];
  
negative.code:       exit 1
      fi
  
      if ! grep -q "YOSYS_VER := $version" Makefile; then
        echo "ERROR: yosys version in Makefile isn't equivalent to version of the nix package (${version}), failing."
        exit 1
      fi
  