# SSL connect to server
    my $retry = 10;
    my $server = undef;
    while ($retry > 0) {
        $server = IO::Socket::SSL->new(
            PeerAddr    => $host,
            PeerPort    => "https",
        );
        if ($server && $server->connected()) {
            print "proxy $$ connected to server\n";
            last;
        } else {
            $retry--;
            warn "proxy $$ connect to server failed: $!,".IO::Socket::SSL::errstr();
            warn "proxy $$ ".($retry ? 'will retry' : 'giving up')."\n";
        }
    }


##</code><code>##

proxy 4730 connect to server failed: Interrupted system call,SSL wants a read first at ./proxy line 110.
proxy 4730 will retry
proxy 4730 connected to server


##</code><code>##

# uname -a
Linux redacted 4.6.0-kali1-amd64 #1 SMP Debian 4.6.4-1kali1 (2016-07-21) x86_64 GNU/Linux

This is perl 5, version 22, subversion 2 (v5.22.2) built for x86_64-linux-gnu-thread-multi
IO::Socket::SSL	2.037
Net::SSLeay 1.77


##</code><code>##

DEBUG: .../IO/Socket/SSL.pm:753: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:763: ssl handshake in progress
DEBUG: ...5.22/IO/Socket.pm:48: ignoring less severe local error 'IO::Socket::IP configuration failed', keep 'SSL wants a read first'
DEBUG: .../IO/Socket/SSL.pm:2777: free ctx 44390832 open=44390832 44011664 43990720
DEBUG: .../IO/Socket/SSL.pm:2782: free ctx 44390832 callback
DEBUG: .../IO/Socket/SSL.pm:2789: OK free ctx 44390832
proxy 4824 connect to server failed: Interrupted system call,SSL wants a read first at ./proxy line 110.