init(Port) args

[cdx08222028]

when using
gen_server:start_link({local, ?SERVER}, ?MODULE, [Port], []).
...................
{ok, LSock} = gen_tcp:listen(lists:nth(1, Port), [{active, true}),
get a problem
** exception exit: function_clause
in function inet_tcp:getserv/1
called as inet_tcp:getserv([1055])

so I tried that
{ok, LSock} = gen_tcp:listen(lists:nth(1, Port), [{active, true}]),
now it goes well.

why does it have this problem?