split dns with dnsmasq and networkmanager broken since 1.10.10 -> 1.14.4

[Divan Santana]

Hi Guix,

I've configured split DNS with dnsmasq and networkmanager and been using
that for quite a while on guix system.

Since a recent update this split DNS setup has stopped working.

Booting the older guix system confirms all just works. I'm not quite
sure what could be wrong.

Here is the details:

Older system profile with these versions works:
kernel 5.2.17
lr29sc29fi0gpy48b2qzbjs6b744m0d6-dnsmasq-2.80
v481hl6d8syq8x9g3hrhmbbdw5qq612l-network-manager-1.10.10

Newer setup with these versions does not:
Kernel 5.3.7
snzrgg9qb6zf3jbshxb4j97ja90ppkng-dnsmasq-2.80
9ciqpyc6jzn1ia607w8s8ziy42jgasv2-network-manager-1.14.4

I've compared the way the processes are started, all looks the same,
except the versions.

Here is a comparison of dnsmasq procs. Working proc on top, broken on bottom.

/gnu/store/lr29sc29fi0gpy48b2qzbjs6b744m0d6-dnsmasq-2.80/sbin/dnsmasq 
--no-resolv --keep-in-foreground --no-hosts --bind-interfaces 
--pid-file=/var/run/NetworkManager/dnsmasq.pid --listen-address=127.0.0.1 
--cache-size=400 --clear-on-reload --conf-file=/dev/null --proxy-dnssec 
--enable-dbus=org.freedesktop.NetworkManager.dnsmasq 
--conf-dir=/etc/NetworkManager/dnsmasq.d
/gnu/store/snzrgg9qb6zf3jbshxb4j97ja90ppkng-dnsmasq-2.80/sbin/dnsmasq 
--no-resolv --keep-in-foreground --no-hosts --bind-interfaces 
--pid-file=/var/run/NetworkManager/dnsmasq.pid --listen-address=127.0.0.1 
--cache-size=400 --clear-on-reload --conf-file=/dev/null --proxy-dnssec 
--enable-dbus=org.freedesktop.NetworkManager.dnsmasq 
--conf-dir=/etc/NetworkManager/dnsmasq.d

Comparison of networkmanager, old and new.

/gnu/store/v481hl6d8syq8x9g3hrhmbbdw5qq612l-network-manager-1.10.10/sbin/NetworkManager
 --config=/gnu/store/ib8k67r4lnqw52lwkw4dzds4a2dj4xwi-NetworkManager.conf 
--no-daemon
/gnu/store/9ciqpyc6jzn1ia607w8s8ziy42jgasv2-network-manager-1.14.4/sbin/NetworkManager
 --config=/gnu/store/ib8k67r4lnqw52lwkw4dzds4a2dj4xwi-NetworkManager.conf 
--no-daemon

Only other thing of interest, on the newer/problematic guix system, it
seems that if you start dnsmasq manually (via sudo) on another port it
seems to function fine.

I can't start it easily on port 53 since NM kills it when NM runs.

so running this to start it in parallel to the broken dnsmasq works:

sudo /gnu/store/snzrgg9qb6zf3jbshxb4j97ja90ppkng-dnsmasq-2.80/sbin/dnsmasq -p 
54 --no-resolv --keep-in-foreground --no-hosts --bind-interfaces 
--pid-file=/var/run/NetworkManager/dnsmasq.pid --listen-address=127.0.0.1 
--cache-size=400 --clear-on-reload --conf-file=/dev/null --proxy-dnssec 
--enable-dbus=org.freedesktop.NetworkManager.dnsmasq 
--conf-dir=/etc/NetworkManager/dnsmasq.d

Testing with dig @127.0.0.1 -p 54 somewhere.example.com shows correct lookup.

But that's not of much help to me since it's on port 54 and not 53.

Any ideas?