anchor.diff:              ok = wait_until(fun() ->
                                       Chains = chains(Workers),
   
  -                                    0 == lists:sum([element(2, rpc:call(?NAME(Name1), erlang, process_info, [W, message_queue_len])) || {{Name1, _}, {ok, W}} <- Workers]) andalso
  +                                    node_debug("Chains: ~p", [sets:to_list(Chains)]),
  +                                    node_debug("message_queue_lens(Workers): ~p should = 0", [message_queue_lens(Workers)]),
  +                                    node_debug("sets:size(Chains): ~p should = 1", [sets:size(Chains)]),
  +                                    node_debug("length(hd(sets:to_list(Chains))): ~p should /= 0", [length(hd(sets:to_list(Chains)))]),
  +
  +                                    0 == message_queue_lens(Workers) andalso
                                       1 == sets:size(Chains) andalso
                                       0 /= length(hd(sets:to_list(Chains)))
                               end, 60*2, 500),
  
positive.code:                                                                             Blocks
                                                                      end, Workers)),
  
                                      0 == lists:sum([element(2, rpc:call(?NAME(Name1), erlang, process_info, [W, message_queue_len])) || {{Name1, _}, {ok, W}} <- Workers]) andalso
                                      1 == sets:size(Chains) andalso
                                      0 /= length(hd(sets:to_list(Chains)))
                              end, 60*2, 500),
  
negative.code:         _ ->
              timer:sleep(Delay),
              wait_until(Fun, Retry-1, Delay)
      end.
  
  %% @private
  message_queue_lens(Workers) ->
      Values = lists:map(fun({{Name1, _}, {ok, W}}) ->
          try
              Result = rpc:call(?NAME(Name1), erlang, process_info, [W, message_queue_len]),
              element(2, Result)
          catch
              _:_ ->
                  0
          end
      end, Workers),
      lists:sum(Values).
  
  %% @private
  chains(Workers) ->
      sets:from_list(lists:foldl(fun({_Node, {ok, W}}, Acc) ->
                                          node_debug("getting blocks for worker: ~p", [W]),
  