>Thanks.  Actually the best way to fix this is to use a 
>.SHELL: name=ksh path=/bin/ksh etc
>in say /etc/mk.conf 

And because its rather undocumented, this is what you want:

.SHELL: name=ksh path=/bin/ksh hasErrCtl=true check="set -e" \
	ignore="set +e" quiet="set +v" filter="set +v" \
	echo="set -v" echoFlag=v errFlag=e

However you'll need to set -j1 before it has any effect.
I'll fix that - as well as adding a ksh entry to the builtin shell specs.

--sjg