Error code 67

[Zeb Kaylor <zmkaylor_(_at_)_chillywilly_(_dot_)_ods_(_dot_)_org>]

uname -a
OpenBSD chillywily 2.7 GENERIC#13 sparc

Version: 2.7

Every time I try to compile a port, I always get the error 

install: unknown group wheel
*** Error code 67

then it says it stops in line 1643 of
/usr/ports/infrastructure/mk/bsd.port.mk

Could you tell me what it is I'm missing?

Thanks,

Zeb Kaylor