The value of DISTDIR cannot be empty - FreeBSD jails upgraded from 9.10-11

I recently upgraded from 9.10 to FreeNas 11.  Surprisingly all the jails seemed to boot after the upgrade, however I'm having an issue upgrading with the freebsd created jails. pkg upgrades workfine, however when try to install from ports using portmaster, I get the following error:

Port Master Packages Needing Upgrading:
libuv-1.18.0
vim-8.0.1365


===>>> The value of DISTDIR cannot be empty
===>>> Aborting update

I don't ever remember setting the value of DISTDIR anywhere on the prior...

The value of DISTDIR cannot be empty - FreeBSD jails upgraded from 9.10-11