anchor.diff:                      end
               catch
                   error:badarg ->
  -                            {error, {unknown_permission, Perm}}
  +                    {error, {unknown_permission, Perm}}
               end;
           _ ->
               {error, {unknown_permission, Perm}}
  
positive.code:             {error, user_exists}
      end.
  
  add_group(Groupname, Options) ->
      case group_exists(Groupname) of
          false ->
  
negative.code:     #context{username=Username, grants=Grants, epoch=os:timestamp()}.
  
  accumulate_grants(Role, Type) ->
      %% The 'all' grants always apply
      All = riak_core_metadata:fold(fun({{_R, _Bucket}, [?TOMBSTONE]}, A) ->
                                            A;
                                       ({{_R, Bucket}, [Permissions]}, A) ->
                                            [{{<<"group/all">>, Bucket},
                                              Permissions}|A]
                                    end, [], metadata_grant_prefix(group),
                                    [{match, {all, '_'}}]),
      {Grants, _Seen} = accumulate_grants([Role], [], All, Type),
      lists:flatten(Grants).
  
  accumulate_grants([], Seen, Acc, _Type) ->
  