anchor.diff:  
   buildPythonPackage rec {
     pname = "cocotb";
  -  version = "1.2.0";
  +  version = "1.3.0";
   
     src = fetchFromGitHub {
       owner = pname;
       repo = pname;
       rev = "v${version}";
  -    sha256 = "091q63jcm87xggqgqi44lw2vjxhl1v4yl0mv2c76hgavb29w4w5y";
  +    sha256 = "0gwd79zm7196fhnbzbdpyvgzsfjfzl3pmc5hh27h7hckfpxzj9yw";
     };
   
     propagatedBuildInputs = [
  
positive.code:       cocotb/share/makefiles/simulators/Makefile.*
      do
        substituteInPlace $f --replace 'shell which' 'shell command -v'
        # replace hardcoded gcc. Remove once https://github.com/cocotb/cocotb/pull/1137 gets merged
        substituteInPlace $f --replace 'gcc' '$(CC)'
        substituteInPlace $f --replace 'g++' '$(CXX)'
      done
    '';
  
    checkInputs = [ swig verilog ];
  
negative.code: 
    meta = with stdenv.lib; {
      description = "Coroutine based cosimulation library for writing VHDL and Verilog testbenches in Python";
      homepage = "https://github.com/cocotb/cocotb";
      license = licenses.bsd3;
      maintainers = with maintainers; [ matthuszagh ];
    };
  