The Mosaic package does not find any of the required X libraries in
the configure phase, nor does it build, without first setting
something like CFLAGS='-O -I/usr/pkg/includes -I/usr/X11R6/includes'
LDFLAGS='-L/usr/pkg/lib -L/usr/X11R6/lib' in the environment.

Likewise, rxvt fails to find Xpm, but in that case, there are no
consequences.

Arguably, there are logical flaws in the configure scripts, but I have
no idea how to fix that. It is evident that Mosaic's configure finds
the X libs and headers, but then doesn't use them for the compiler
tests. Setting CFLAGS and LDFLAGS (before configure) is an easy
work-around.

What's the right way to fix this? In the Makefile for just the
programs that need it, or some kind of test in bsd.pkg.mk?