> > > USE_MOTIF=YES
> > 
> > The problem is your use of USE_MOTIF in /etc/mk.conf - it's not meant
> > for that kind of use.  For example, there is no mention of USE_MOTIF
> > in pkgsrc/mk/mk.conf.example, and in the packages(7) manual page,
> > under the section: 
> 
> The FreeBSD /etc/make.conf (aside:  do these HAVE to be different?) defines
> the following:

No, they don't *have* to be different. They just are. As you point out,
they contain different definitions.
 
> # If you have Motif on your system, uncomment this.
> #
> #HAVE_MOTIF=    yes
> #
> # If the default location of the Motif library (specified below) is NOT
> # appropriate for you, uncomment this and change it to the correct value.
> # If your motif is in ${X11BASE}/lib, you don't need to touch this line.
> #
> #MOTIFLIB=      -L${X11BASE}/lib -lXm

What FreeBSD do in the privacy of their own homes is their business. 

NetBSD doesn't use HAVE_MOTIF - there's no need, we can work out
automatically if Motif or Lesstif is installed.  For the means of
doing this, see pkgsrc/x11/lesstif/Makefile