I found the magic:

cd /path/to/port
make -dA 2>&1 | less

Thus I found "/etc/make.conf", which says the version of Perl to use. I thought that

use.perl port

just said "ln -s /usr/{,local/}bin/perl", but apparently it updates other things, too. /etc

I'm trying to figure out how other people set up their server equipment. Racks are a given; I'm looking information about patch panels, cabling, labeling, the console server...

sage-members had a good discussion about how to label cables, from which I distill the rule "label all cables at both ends (and perhaps every 10 feet) with unique, random numbers."

I don't know much about how console servers are typically used, nor how patch panels are set up.