Etcupdate runtime has more than doubled....Why?

For some time now I've been using etcupdate on a self-hosting
armv7 (RPi2) system. Lately, the runtime for etcupdate after
a world/kernel update from source has seemingly more than doubled.
It used to take less than one hour, now it's past two hours and
not done yet. The last process is a series of c++ processes which 
take most of the added time.

Apart from tracking -current the machine doesn't do much, but
I didn install a /usr/ports directory recently though it's only
been used to build named. The slowdown in etcupdate seems to
have appeared following that change.

Might the addition of a ports tree have increased etcupdate's
run time, and is there in any case some housecleaning that will
speed it up?

Thanks for reading,

bob prohaska