nstat is a tool for collecting linux network statistics. I use it in my monitoring stack to collect information about UDP data loss. The command maintains state, and on rare occasions, that state becomes corrupt. Corrupted state results in the command dumping core without any other explanation.
$ nstat Aborted (core dumped)
strace of the command is similarly unhelpful. The best way I've found to rectify this situation is to reset the command's history