Woot! Its zeromq stuff. My new test app:

#!/usr/bin/perl

use common::sense;
use ZeroMQ ':all';
use Data::Dumper;

my $ctx = ZeroMQ::Context->new();

my $sock = $ctx->socket(ZMQ_PULL);
$sock->setsockopt(ZMQ_HWM, 500);
$sock->bind('tcp://*:5558'); 

$SIG{HUP}  = sub {
  print "got hup\n";
};

while (1)
{
  my $msg = $sock->recv();
  print "got message\n";
  print Dumper(\$msg);
}
[download]

after I sighup it, I get:

got hup
got message
$VAR1 = \undef;
[download]

In real code, I call $msg->data() next which when $msg is undef I can see that killing the script.

Its kinda weird that SIGHUP makes $sock->recv() return, but at least I can code around that.

thanks again,

-Andy