anchor.diff:  , gmp-static
   , verilog
   , asciidoctor
  -, tex }:
  +, tex
  +, which
  +}:
   
   let
     ghcWithPackages = ghc.withPackages (g: (with g; [ old-time regex-compat syb split ]));
   
   in stdenv.mkDerivation rec {
     pname = "bluespec";
  -  version = "2021.07";
  +  version = "2022.01";
   
     src = fetchFromGitHub {
       owner = "B-Lang-org";
       repo = "bsc";
       rev = version;
  -    sha256 = "0gw8wyp65lpkyfhv3laazz9qypdl8qkp1j7cqp0gv11592a9p5qw";
  +    sha256 = "sha256-ivTua3MLa8akma3MGkhsqwSdwswYX916kywKdlj7TqY=";
  +  };
  +
  +  yices-src = fetchurl {
  +    url = "https://github.com/B-Lang-org/bsc/releases/download/${version}/yices-src-for-bsc-${version}.tar.gz";
  +    sha256 = "sha256-ey5yIIVFZyG4EnYGqbIJqmxK1rZ70FWM0Jz+2hIoGXE=";
     };
   
     enableParallelBuilding = true;
  
positive.code: 
    postUnpack = ''
      mkdir -p $sourceRoot/src/vendor/yices/v2.6/yices2
      # XXX: only works because yices.src isn't a tarball.
      cp -av ${yices.src}/* $sourceRoot/src/vendor/yices/v2.6/yices2
      chmod -R +rwX $sourceRoot/src/vendor/yices/v2.6/yices2
    '';
  
  
negative.code:     libX11 # tcltk
      tcl
      tk
      which
      xorg.libXft
      zlib
    ];
  