SOLVED: sudo dumping core on recent current

Kia ora,
I have found the root cause of my trouble.

The pkgsrc sandbox creation script doesn't create /var/db in the chroot 
sandbox. This in turn left sudo without any viable locations for vardir 
when searching for them in configure. Finally, the sudoers plugin will 
crash if no vardir has been configure for the lecture stamp file.

I saw one success and one failure in ts_secure_opendir() because that 
function is used for both the auth timestamp and the lecture stamp. Only 
the lecture stamp uses vardir, so there was only one failure.

My older package worked fine because it wasn't build in a pkgsrc sandbox 
and so vardir had been configure to be /var/db.

Thank you all for your good advice.

Ngā mihi,
Lloyd