anchor.diff:    clog = buildFromGitHub {
       version = 1;
       date = "2016-06-09";
  -    rev = "ae8f8315ad044b86ced2e0be9e3598e9dd94f38e";
  +    rev = "ae8f8315ad044b86ced2e0be9e3598e9dd94f38a";
       owner = "couchbase";
       repo = "clog";
       sha256 = "185c10ab80cn4jxdp915h428lm0r9zf1cqrfsjs71im3w3ankvsn";
  
positive.code:   };
  
    rcrowley_go-metrics = buildFromGitHub {
      version = 2;
      rev = "1f30fe9094a513ce4c700b9a54458bbb0c96996c";
      date = "2016-11-28";
      owner = "rcrowley";
      repo = "go-metrics";
      sha256 = "1bz5x3i4xr1nnlknliqy5v2544qmr2jw7qb9ssdr9w68l330fpaa";
      propagatedBuildInputs = [ stathat ];
    };
  
  
negative.code:     version = 3;
      owner = "minio";
      repo = "dsync";
      date = "2017-11-22";
      rev = "ed0989bc6c7b199f749fa6be0b7ee98d689b88c7";
      sha256 = "07izm9hghc6pilnvs32ag531c7q1cf6aw8h2457dn2sz8m8wzp5s";
    };
  
    du = buildFromGitHub {
  