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...
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/...
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]...
ipupdate compiles under libgcc-5 on Ubuntu 16.04.2 LTS but segfaults on execute