anchor.diff:      ln -s ../yosys-abc abc
       make config-${if stdenv.cc.isClang or false then "clang" else "gcc"}
       echo 'ABCREV := default' >> Makefile.conf
  -    makeFlags="PREFIX=$out $makeFlags"
   
       # we have to do this ourselves for some reason...
       (cd misc && ${protobuf}/bin/protoc --cpp_out ../backends/protobuf/ ./yosys.proto)
  
positive.code:   nativeBuildInputs = [ pkgconfig ];
    buildInputs = [ tcl readline libffi python3 bison flex protobuf zlib ];
  
    makeFlags = [ "ENABLE_PROTOBUF=1" ];
  
    patchPhase = ''
      substituteInPlace ../yosys-abc/Makefile \
  
negative.code: { stdenv
  , bison
  , fetchFromGitHub
  , flex
  , libffi
  , pkgconfig
  , protobuf
  , python3
  , readline
  , tcl
  , verilog
  , zlib
  }:
  
  with builtins;
  