anchor.diff:      meta.useUnstable = true;
     };
   
  +  fastuuid = buildFromGitHub {
  +    version = 3;
  +    date = "2015-01-06";
  +    rev = "6724a57986aff9bff1a1770e9347036def7c89f6";
  +    owner  = "rogpeppe";
  +    repo   = "fastuuid";
  +    sha256 = "1q04xarwz0f2jlhz3d9myxx8ikrbynj5pyhhcsz25dc56kc2gpfz";
  +  };
  +
     fileutil = buildFromGitHub {
       version = 3;
       date = "2017-11-07";
  
positive.code:       tomb_v1
      ];
      date = "2017-08-14";
    };
  
    tar-split = buildFromGitHub {
  
negative.code:     sha256 = "1nrw7xp2i4whgr91ffl9j9fm5r8icgxxvny3xilkap8zsmfhbkqh";
    };
  
    persistent-cookiejar = buildFromGitHub {
      version = 3;
      date = "2017-10-26";
      owner  = "juju";
      repo   = "persistent-cookiejar";
      rev = "d5e5a8405ef9633c84af42fbcc734ec8dd73c198";
      sha256 = "1knkwj44wq85wkxb69v3yh5v9ddix63a2saq49077yd7l13j6rmd";
      excludedPackages = "test";
      propagatedBuildInputs = [
        errgo_v1
        go4
        net
        retry_v1
      ];
    };
  
    pester = buildFromGitHub {
      version = 3;
      owner = "sethgrid";
  