gle needs Xmu with needs libXext

I was ./configure-ing gle-3.1.0 and it complained:
/usr/lib/libXmu.so: undefined reference to `XShapeCombineMask'

So I tracked it down:

"objdump -x /usr/lib/libXmu.so" says

00000000         *UND*  00000000              XShapeCombineMask

/usr/lib/libXext.so has:
00008349 g     F .text  00000128              XShapeCombineMask

So I was able to work-around this by making sure that the configure script
also used -lXext.

gle doesn't use pkg-config (as far as I can tell). And I assume this is
could be common for other software builds.

Is libXext something that should be in the libXmu.so and libXi.so
libraries?

Or what is the suggested way to handle this?

Because with standard XFree86 libraries, including -lXext is not needed.

By the way, I work on the pkgsrc packing system, and I need to figure out
a way that will work best for users who choose our xlibs or choose
XFree86-libs. I guess I could make it so if xlibs is used and when using
libXmu or libXi to always do LDFLAGS+=	-lXext.

Is that the best way?

Thank you,

   Jeremy C. Reed
   http://bsd.reedmedia.net/