[XForms] error compiling on OSX

[jos]

I’m trying to compile some code on OSX Sierra 10.12.6
I’ve compiled forms-1.3.9 and I’m trying to statically link my code against it.
Unfortunately I’m getting some errors, see below.
Can anybody maybe explain to me what is wrong?

Jos

cc -L/usr/X11R6/lib -lX11 -lm /usr/local/lib/libforms.a 
/usr/local/lib/libsndfile.a -lm -o formant formant.o safe_alloc.o mparcoe.o \
        mcoewav.o msetcfg.o voc_inout.o std.o fft2pixmap.o pup.o cursor.o 
show_params.o act_slot_1.o act_slot_2.o act_slot_3.o act_slot_4.o act_slot_5.o 
create_slot_1.o create_slot_2.o create_slot_3.o create_slot_4.o create_slot_5.o 
slot_1_cb.o slot_2_cb.o slot_3_cb.o slot_4_cb.o slot_5_cb.o  -L/usr/X11R6/lib 
-lX11 -lm /usr/local/lib/libforms.a /usr/local/lib/libsndfile.a -lm
Undefined symbols for architecture x86_64:
  "_XpmAttributesSize", referenced from:
      _fl_create_from_pixmapdata in libforms.a(pixmap.o)
      _fl_read_pixmapfile in libforms.a(pixmap.o)
  "_XpmCreatePixmapFromData", referenced from:
      _fl_create_from_pixmapdata in libforms.a(pixmap.o)
  "_XpmFreeAttributes", referenced from:
      _handle_pixmap in libforms.a(pixmap.o)
      _change_pixmap in libforms.a(pixmap.o)
      _cleanup_pixmapbutton in libforms.a(pixmap.o)
      _fl_free_pixmap_pixmap in libforms.a(pixmap.o)
  "_XpmReadFileToPixmap", referenced from:
      _fl_read_pixmapfile in libforms.a(pixmap.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: [formant] Error 1 (ignored)