#6 ipupdate compiles under libgcc-5 on Ubuntu 16.04.2 LTS but segfaults on execute

I am able to build ipupdate successfully on Ubuntu 16.04.2 successfully, but on execution the app segfaults.

Attaching core file and build directory for debugging.

./ipupdate
getconfig: loading '/etc/ipupdate.conf'
Detected IP: 24.211.238.20
Segmentation fault (core dumped)

[Anonymous]

Here is the information on the gcc installation:

gcc/xenial,now 4:5.3.1-1ubuntu1 amd64 [installed]
gcc-5/xenial-updates,xenial-security,now 5.4.0-6ubuntu1~16.04.4 amd64 [installed,automatic]
gcc-5-base/xenial-updates,xenial-security,now 5.4.0-6ubuntu1~16.04.4 amd64 [installed]
gcc-6-base/xenial,now 6.0.1-0ubuntu1 amd64 [installed]
libcaca0/xenial,now 0.99.beta19-2build2~gcc5.2 amd64 [installed,automatic]
libgcc-5-dev/xenial-updates,xenial-security,now 5.4.0-6ubuntu1~16.04.4 amd64 [installed,automatic]
libgcc1/xenial,now 1:6.0.1-0ubuntu1 amd64 [installed]

[Anonymous]

After looking at the whatismyip code behavior, I think that I have found a clue as to what the problem is. It looks like whatismyip is using IPv6 to make its call on my machine. I have IPv6 enabled (and would prefer to leave it enabled) and as a result, whatismyip is not returning the expected IPv4 address, which is most likely causing the segfault.

Experimentation:

$ ./whatismyip
0

$

Using wget to pull-up the whatismyip.com web site:

$ wget https://www.whatismyip.com/
--2017-07-23 11:30:11-- https://www.whatismyip.com/
Resolving www.whatismyip.com (www.whatismyip.com)... 2400:cb00:2048:1::681b:c05c, 2400:cb00:2048:1::681b:c15c, 104.27.193.92, ...
Connecting to www.whatismyip.com (www.whatismyip.com)|2400:cb00:2048:1::681b:c05c|:443... connected.
HTTP request sent, awaiting response... 403 Forbidden
2017-07-23 11:30:12 ERROR 403: Forbidden.

Is there a way to make whatismyip prefer IPv4 instead of IPv6?

[Anonymous]

OK, as I get more familiar with what ipupdate is doing, I find that most likely the issue is not with the 'whatismyip' app, since the call to app 'dollardns' is working properly...

Continuing to look further...