One useful feature that LWP::Debug provided (in an imprecise and troublesome way) was network traffic monitoring. The following section provide some hints about recommened replacements.
Another approach it to use a debugging HTTP proxy server and make LWP direct all its traffic via this one. Call "$ua->proxy" to set it up and then just use LWP as before.
For less precise monitoring needs just setting up a few simple handlers might do. The following example sets up handlers to dump the request and response objects that pass through LWP:
use LWP::UserAgent;
$ua = LWP::UserAgent->new;
$ua->default_header('Accept-Encoding' => scalar HTTP::Message::decodable());
$ua->add_handler("request_send", sub { shift->dump; return });
$ua->add_handler("response_done", sub { shift->dump; return });
$ua->get("http://www.example.com");