anchor.diff:  
     src = fetchurl {
       url = "${webpage}/releases/${pname}-${version}.tbz";
  -    sha256 = "1czd2fq85hy24w5pllarsq4pvbx9rda5zdikxfxdng8s9kff2h3f";
  +    sha256 = "07h9a464v0x066mjg3ldkaq94ah47b7rvh54z4rndrg7v6bk7kyp";
     };
   
     buildInputs = [ ocaml findlib ocamlbuild topkg ];
  
positive.code:     module. An API allows to implement new renderers.
      '';
      homepage = "${webpage}";
      platforms = ocaml.meta.platforms or [];
      license = licenses.bsd3;
      maintainers = [ maintainers.jirkamarsik ];
    };
  }
  
negative.code:   inherit (stdenv.lib) optionals versionAtLeast;
  
    pname = "vg";
    version = "0.9.1";
    webpage = "http://erratique.ch/software/${pname}";
  in
  
  