Incorrect IP address with --sourceaddr gives not error message

[matsduf]

The documentation for --sourceaddr says

	--sourceaddr STR       Source IP address used to send queries.
	                       Setting an IP address not correctly configured
	                       on a local network interface causes cryptic
	                       error messages.

It is expected that some error message comes out if the IP address is wrong (not configured on the interface), but when --sourceaddr is used in that way nothing comes out that gives a clue.

Compare a test with correct IP address with a one that is not on the interface (IPv6 disabled):

$ zonemaster-cli --test basic --level info zonemaster.net --no-ipv6 --sourceaddr 172.31.10.109 # Correct IP address
Seconds Level     Message
======= ========= =======
   0.00 INFO      Using version v4.6.2 of the Zonemaster engine.
   0.28 INFO      Parent domain 'net' was found for the tested domain.
   1.28 INFO      Nameserver ns2.nic.fr/192.93.0.4 listed these servers as glue: ns2.nic.fr.,nsa.dnsnode.net.,nsp.dnsnode.net.,nsu.dnsnode.net..
   1.28 INFO      Nameserver nsa.dnsnode.net/194.58.192.46 listed these servers as glue: ns2.nic.fr.,nsa.dnsnode.net.,nsp.dnsnode.net.,nsu.dnsnode.net..
   1.28 INFO      Nameserver nsp.dnsnode.net/194.58.198.32 listed these servers as glue: ns2.nic.fr.,nsa.dnsnode.net.,nsp.dnsnode.net.,nsu.dnsnode.net..
   1.29 INFO      Nameserver nsu.dnsnode.net/185.42.137.98 listed these servers as glue: ns2.nic.fr.,nsa.dnsnode.net.,nsp.dnsnode.net.,nsu.dnsnode.net..
   1.29 INFO      Functional nameserver found. "A" query for www.zonemaster.net test skipped.

$ zonemaster-cli --test basic --level info zonemaster.net --no-ipv6 --sourceaddr 172.31.10.110 # Incorrect IP address
Seconds Level     Message
======= ========= =======
   0.00 INFO      Using version v4.6.2 of the Zonemaster engine.
   0.02 INFO      Parent domain '.' was found for the tested domain.
   0.04 CRITICAL  No NS records for tested zone from parent. NS tests skipped.

Preferably something should come out that indicate the error.