Upgrade from 7.0.2 to 8.0_BETA: some trouble with sockets (I think)

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

Hello,

I'm upgrading a test server from NetBSD 7.0.2 to 8.0_BETA. I have built 
8.0 from sources for amd64 last friday.

Two daemons (built from pkgsrc) refuse to work as expected:
- squid always returns "document contains no data". I have deleted and 
recreated an empty cache volume without any result. My server doesn't 
send any http packets on its WAN interface;
- mysql that runs fine when I connect to this database server from 
localhost:

legendre# mysql -hlocalhost -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.35 Source distribution

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights 
reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input 
statement.

mysql> ^DBye

When I try to access to database from another client, connection was 
closed by server :
root@hilbert:/etc/zm# mysql -uzmuser -h192.168.10.128 -p
Enter password:
ERROR 2013 (HY000): Lost connection to MySQL server at 'reading initial 
communication packet', system error: 104 "Connection reset by peer"

Of course, zmuser exists and is authorized. And before upgrade, zmuser 
was able to connect to database and squid ran fine. Configurations of 
mysql and squid haven't been modified.

I have tried with or without NPF with the same result. With tcpdump, I 
can see for example on mysql client :
root@hilbert:~# tcpdump port 3306
tcpdump: verbose output suppressed, use -v or -vv for full protocol 
decode
listening on enp3s0, link-type EN10MB (Ethernet), capture size 262144 
bytes
14:14:51.734354 IP 192.168.10.103.59516 > 192.168.10.128.mysql: Flags 
[S], seq 3338130626, win 29200, options [mss 1460,sackOK,TS val 25821788 
ecr 0,nop,wscale 7], length 0
14:14:51.734458 IP 192.168.10.128.mysql > 192.168.10.103.59516: Flags 
[S.], seq 3511699100, ack 3338130627, win 32768, options [mss 
1460,nop,wscale 3,sackOK,TS val 1 ecr 25821788], length 0
14:14:51.734490 IP 192.168.10.103.59516 > 192.168.10.128.mysql: Flags 
[.], ack 1, win 229, options [nop,nop,TS val 25821788 ecr 1], length 0
14:14:51.734581 IP 192.168.10.128.mysql > 192.168.10.103.59516: Flags 
[R], seq 3511699101, win 0, length 0

All other daemons seem to run as expected.

I have tried to rebuild mysql and squid from pkgsrc but it doesn't fix 
this issue.

All ideas to solve this issue are welcome.

Best regards,

JKB