anchor.diff:                     end},
            #{desc => "bind socket",
              cmd  => fun(#{sock := Sock, local_sa := LSA}) ->
  -                           sock_bind(Sock, LSA),
  -                           ok
  +                           case socket:bind(Sock, LSA) of
  +                               {ok, _Port} ->
  +                                   ?SEV_IPRINT("src bound"),
  +                                   ok;
  +                               {error, Reason} = ERROR ->
  +                                   ?SEV_EPRINT("src bind failed: ~p", [Reason]),
  +                                   ERROR
  +                           end
                      end},
            #{desc => "announce ready (init)",
              cmd  => fun(#{tester := Tester, sock := Sock}) ->
  
positive.code: %% don't clash.
  mk_unique_path() ->
      [NodeName | _] = string:tokens(atom_to_list(node()), [$@]),
      ?LIB:f("/tmp/esock_~s_~w", [NodeName, erlang:system_time(nanosecond)]).
  
  which_local_socket_addr(local = Domain) ->
      #{family => Domain,
        path   => mk_unique_path()};
  
negative.code:                    end},
           #{desc => "bind src",
             cmd  => fun(#{sock_src := Sock, lsa_src := LSA}) ->
                             case socket:bind(Sock, LSA) of
                                 {ok, _Port} ->
                                     ?SEV_IPRINT("src bound"),
                                     ok;
                                 {error, Reason} = ERROR ->
                                     ?SEV_EPRINT("src bind failed: ~p", [Reason]),
                                     ERROR
                             end
                     end},
           #{desc => "sockname src socket",
             cmd  => fun(#{sock_src := Sock} = State) ->
  