anchor.diff:      rev = "b965b613227fddccbfffe13eae360ed3fa822f8d";
       name = "beorn7.perks-${stdenv.lib.strings.substring 0 7 rev}";
       goPackagePath = "github.com/beorn7/perks";
  +
       src = fetchFromGitHub {
         inherit rev;
         owner = "beorn7";
  
positive.code:       owner = "mreiferson";
        repo = "go-options";
        sha256 = "0hg0n5grcjcj5719rqchz0plp39wfk3znqxw8y354k4jwsqwmn17";
      };
    };
  
  
negative.code:   ## OFFICIAL GO PACKAGES
  
    crypto = buildGoPackage rec {
      rev = "4d48e5fa3d62b5e6e71260571bf76c767198ca02";
      name = "go-crypto-${rev}";
      goPackagePath = "golang.org/x/crypto";
  
      src = fetchFromGitHub {
        inherit rev;
        owner  = "golang";
        repo   = "crypto";
        sha256 = "0plvjv56afb02p7l3c2zfwffnhscmc3f0ckj1gls9ay6vj85y7l8";
      };
    };
  
  