NetBSD Guide section 8.9 needs fixes
near

     As usual, both pkg_add and make install will fetch the needed packages
     automatically, so there is no need to go through the dependencies
     manually.

     # cd /usr/pkgsrc/x11/windowmaker
     # make depends-list
     xpm-3.4k
     jpeg-6b
     pkglibtool-1.2p2
     giflib-3.0
     libproplist-0.9.1
     tiff-3.5.2

First, there is no target 'depends-list' that shows dependancies
(make show-var VARNAME=_ALL_DEPENDS ?).
Second, it is be better to change x11/windowmaker to wm/windowmaker.

-- 
Best regards, Aleksey Cheusov.