ports/114890: building science/xmakemol fails with libGL.

[Tsurutani Naoki]

Pav Lucistnik wrote:

>> I want to know who should install glwMDrawingArea etc.
> 
> libGLw (w is for widgets).

Thank you for your reply.
I found no glwMDrawingArea* in /usr/local/lib/libGLw.so.1,
but libGLw.so.1 in downloaded package has it.
I investigated the log in pointyhat 
(http://pointyhat.freebsd.org/errorlogs/i386-6-full-logs/libGLw-6.5.3.log),
and found a difference; "-D__GLX_MOTIF=1" is not used while
building the only one C source file on my host, but on pointyhat it was used.
I build library with just the same way shown in the log on pointyhat,
and found that glwMDrawingArea* are include in libGLw.so.1.

I wonder why this happens.
Variable CFLAGS is set in /etc/make.conf, and removing this from
/etc/make.conf allows building libGLw with glwMDrawingArea*,
just like on the pointyhat.
Setting CFLAGS in /etc/make.conf is allowed, as far as the value
is not so confusing one.
Why CFLAGS in the Makefile is overwritten by /etc/make.conf ?
Is that the correct way of setting variables ?

Anyway, this is not a bug of science/xmakemol.
Thank you for your assistance.