anchor.diff:  
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
  -send_failed_str(Reason) ->
  -    ?F("Send failed: ~w", [Reason]).
  -
  -connect_failed_str(Reason) ->
  -    ?F("Connect failed: ~w", [Reason]).
  -
  -listen_failed_str(Reason) ->
  -    ?F("Listen failed: ~w", [Reason]).
  -
  -accept_failed_str(Reason) ->
  -    ?F("Accept failed: ~w", [Reason]).
  -
  -port_failed_str(Reason) ->
  -    ?F("Port failed: ~w", [Reason]).
  -
  -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  -
   
   -define(ACTIVE_N, 20).
   
  -%% 30-second test for gen_tcp in {active, N} mode, ensuring it does not get stuck.
  +%% 30-second test for gen_tcp in {active, N} mode,
  +%% ensuring it does not get stuck.
   %% Verifies that erl_check_io properly handles extra EPOLLIN signals.
   bidirectional_traffic(Config) when is_list(Config) ->
       ?TC_TRY(bidirectional_traffic,
               fun() -> do_bidirectional_traffic(Config) end).
   
  -do_bidirectional_traffic(_Config) ->
  +do_bidirectional_traffic(Config) ->
       ?P("begin"),
       Workers = erlang:system_info(schedulers_online) * 2,
       ?P("Use ~w workers", [Workers]),
       Payload = crypto:strong_rand_bytes(32),
       ?P("create listen socket"),
  -    {ok, LSock} = gen_tcp:listen(0, [binary, {packet, 0}, {active, false}, {reuseaddr, true}]),
  +    {ok, LSock} = ?LISTEN(Config,
  +			  0,
  +			  [binary,
  +			   {packet, 0},
  +			   {active, false},
  +			   {reuseaddr, true}]),
       %% get all sockets to know failing ends
       {ok, Port} = inet:port(LSock),
       ?P("listen socket port number ~w", [Port]),
       Control = self(),
       ?P("create ~w receivers", [Workers]),
  -    Receivers = [spawn_link(fun () -> exchange(LSock, Port, Payload, Control) end) || _ <- lists:seq(1, Workers)],
  +    Receivers = [spawn_link(fun () -> 
  +				    exchange(Config, LSock, Port, Payload, Control)
  +			    end) || _ <- lists:seq(1, Workers)],
       ?P("await the result"),
       Result =
  +	%% If any of the receivers report, we have an error
           receive
               {timeout, Socket, Total} ->
                   ?P("timeout msg for ~p: ~w", [Socket, Total]),
                   {fail, {timeout, Socket, Total}};
  -            {error, Socket, Reason} ->
  +	    {error, Socket, Reason} ->
                   ?P("error msg for ~p: ~p", [Socket, Reason]),
                   {fail, {error, Socket, Reason}}
           after 30000 ->
                   %% if it does not fail in 30 seconds, it most likely works
  -                ?P("timeout => success?"),
  +                ?P("timeout => success"),
                   ok
           end,
  -    ?P("terminate receivers"),
  +    ?P("ensure all receivers terminated"),
       [begin unlink(Rec), exit(Rec, kill) end || Rec <- Receivers],
       ?P("done"),
       Result.
   
  -exchange(LSock, Port, Payload, Control) ->
  +    
  +exchange(Config, LSock, Port, Payload, Control) ->
       %% spin up client
       _ClntRcv = spawn(
           fun () ->
                   ?P("connect"),
                   {ok, Client} =
  -                    gen_tcp:connect("localhost",
  -                                    Port,
  -                                    [binary, {packet, 0}, {active, ?ACTIVE_N}]),
  +                    ?CONNECT(Config,
  +			     "localhost",
  +			     Port,
  +			     [binary, {packet, 0}, {active, ?ACTIVE_N}]),
                   ?P("connected: ~p", [Client]),
                   send_recv_loop(Client, Payload, Control)
           end),
  
positive.code:                 (catch inet:getstat(Socket)),
                  (catch prim_inet:getstatus(Socket)),
                  (catch erlang:port_info(Socket))]),
              Control ! {error, Socket, Other}
      after 2000 ->
              %% no data received in 2 seconds, test failed
              ?P("[recv] received nothing when total received: ~w"
                 "~n      Socket:      ~p"
                 "~n      Port stat:   ~p"
                 "~n      Port status: ~p"
                 "~n      Port Info:   ~p",
                 [Total,
                  Socket,
                  (catch inet:getstat(Socket)),
                  (catch prim_inet:getstatus(Socket)),
                  (catch erlang:port_info(Socket))]),
              Control ! {timeout, Socket, Total}
      end.
  
negative.code:             inet:setopts(Socket, [{active, ?ACTIVE_N}]),
              recv(Socket, Total, Control);
          {tcp_closed, Socket} ->
              ?P("[recv] closed when total received: ~w"
                 "~n      Socket Info: ~p",
  	       [Total,
                  (catch gen_tcp_socket:info(Socket))]),
  	    ok;
          Other when is_port(Socket) ->
              ?P("[recv] received unexpected when total received: ~w"
                 "~n      ~p"
                 "~n      Socket:      ~p"
  