anchor.diff:  
     google-cloud-go = buildFromGitHub {
       version = 3;
  -    date = "2017-11-27";
  -    rev = "e943e4a209a366ebdb8f5cbdb2b726a2116e1967";
  +    date = "2017-11-28";
  +    rev = "28b507a1143b9134490384bc95088187dde1b96a";
       owner = "GoogleCloudPlatform";
       repo = "google-cloud-go";
  -    sha256 = "01dhlrdyf6bvssx9x0siw22chmprw6gbpgc8fjsplshxlib7ag94";
  +    sha256 = "1w9pnmij47f3qpdq8dlqbrvbcy1xxvvd69p7l23kcr3hmj2q95gn";
       goPackagePath = "cloud.google.com/go";
       goPackageAliases = [
         "google.golang.org/cloud"
  
positive.code: 
    goorgeous = buildFromGitHub {
      version = 3;
      rev = "v2.0.0";
      owner = "chaseadamsio";
      repo = "goorgeous";
      sha256 = "0pamhar56hpq9riiwsr9lm4rms3q7rb3w4nf1y32racp4as1hgfy";
      propagatedBuildInputs = [
        blackfriday
        sanitized-anchor-name
      ];
    };
  
    gopass = buildFromGitHub {
  
negative.code:     version = 3;
      owner = "russross";
      repo = "blackfriday";
      rev = "6d1ef893fcb01b4f50cb6e57ed7df3e2e627b6b2";
      sha256 = "0wdsyblcch0yk0hzr57m6mapfjdifp7zs9lk2ivvi891rfznc9mi";
      propagatedBuildInputs = [
        sanitized-anchor-name
      ];
      meta.useUnstable = true;
      date = "2017-10-11";
    };
  
    blake2b-simd = buildFromGitHub {
  