Comment 4 for bug 1761096

I confirm that every second
 $ systemctl restart dnsmasq
hangs

Also I confirm that removing squid resolved the situation.

I found that it does this:
1. /bin/sh /etc/init.d/dnsmasq systemd-stop-resolvconf
2. /bin/sh /etc/init.d/dnsmasq systemd-start-resolvconf

Both will call hooks like:

0 0 11642 11634 20 0 4364 660 wait S ? 0:00 \_ run-parts --arg=-a --arg=lo.dnsmasq /etc/resolvconf/update.d
0 0 11659 11642 20 0 4364 664 wait S ? 0:00 \_ run-parts /etc/resolvconf/update-libc.d
0 0 11672 11659 20 0 4504 704 wait S ? 0:00 \_ /bin/sh /etc/resolvconf/update-libc.d/squid
0 0 11673 11672 20 0 4504 1648 wait S ? 0:00 \_ /bin/sh /usr/sbin/invoke-rc.d squid reload
4 0 11691 11673 20 0 24888 1388 poll_s S ? 0:00 \_ systemctl reload squid.service

This is what actually times out - the squid hook.

The "systemctl reload squid.service" call seems to take too long every second time?!

A single "systemctl reload squid.service" for these seems to take ~100 seconds for me.
OTOH a direct call to it is fast every time.

This needs to be debugged in detail, but seems well reproducible.