Not a GLOB reference at ...IO/Select.pm line 61 - perl

Question

I am passing an IO::Select object as handle to IO::Select::add and getting the following error:
Not a GLOB reference at ...IO/Select.pm line 61
This worked for years and since a couple of days (weeks) people are beginning to get the error. Looking online I was not able to find out if I was using the call in the wrong way or if some recent perl or DNS::Resolver update could be the cause of the problem.
I am doing the following
#!/usr/bin/perl
use IO::Select;
use Net::DNS;
# create a resolver object
my $res = Net::DNS::Resolver->new();
# create an IO::Select object
my $sel = IO::Select->new();
# perform the background DNS query
my $sock = $res->bgsend('corti.li');
# adding the socket generates the error
$sel->add($sock);
Adding some debugging I don't see anything wrong:
#!/usr/bin/perl
use Data::Dumper;
use IO::Select;
use Net::DNS;
# create a resolver object
my $res = Net::DNS::Resolver->new();
warn Dumper $res;
# create an IO::Select object
my $sel = IO::Select->new();
warn Dumper $sel;
# perform the background DNS query
my $sock = $res->bgsend('corti.li');
warn Dumper $sock;
# adding the socket generates the error
$sel->add($sock);
produces
$VAR1 = bless( {
'force_v4' => 0,
'retrans' => 5,
'persistent_udp' => 0,
'adflag' => 0,
'force_v6' => 0,
'port' => 53,
'answerfrom' => '',
'prefer_v6' => 0,
'defnames' => 1,
'tcp_timeout' => 120,
'udp_timeout' => 30,
'igntc' => 0,
'udppacketsize' => 0,
'dnsrch' => 1,
'recurse' => 1,
'srcaddr' => 0,
'persistent_tcp' => 0,
'retry' => 4,
'cdflag' => 0,
'nameserver4' => [
'129.132.98.12'
],
'searchlist' => [
'd.ethz.ch',
'ethz.ch'
],
'tsig_rr' => undef,
'nameserver6' => [
'2001:67c:10ec::c'
],
'usevc' => 0,
'dnssec' => 0,
'debug' => 0,
'errorstring' => 'unknown error or no error',
'srcport' => 0
}, 'Net::DNS::Resolver' );
$VAR1 = bless( [
undef,
0
], 'IO::Select' );
$VAR1 = bless( [
',
1,
undef,
undef,
undef,
[
bless( \*Symbol::GEN0, 'IO::Socket::IP' ),
1448125508,
'129.132.98.12',
54103
]
], 'IO::Select' );
Not a GLOB reference at /Users/corti/perl5/perlbrew/perls/perl-5.22.0/lib/5.22.0/darwin-2level/IO/Select.pm line 61.
I am using Perl 5.22 and Net::DNS 1.03
Using Perl 5.18 and Net::DNS 0.74 the code works.
Am I doing something wrong or it is a bug?

Answer 1

The problem is caused by a change in the API of Net::DNS::Resolver bgsend
See #108745: Net::DNS::Resolver bgsend