build broken: libxml - i386 vs. X86_64 - configure problem

[David Reitter]

The libxml bindings or something else related to XML broke the build for me (on 
a mac), due to the chosen build architecture being 64-bit (chosen by default, 
and that is correct), but the library being i386:


address@hidden:~/em24.git emacs24$ ./configure --with-ns
...
checking build system type... x86_64-apple-darwin10.4.0
checking host system type... x86_64-apple-darwin10.4.0
...
checking for libxml-2.0 > 2.2.0... yes
checking LIBXML2_CFLAGS... -I/opt/local/include/libxml2 -I/opt/local/include  
checking LIBXML2_LIBS... -L/opt/local/lib -lxml2 -lpthread -lz -liconv -lm  
...


gcc  -prebind -framework AppKit -Xlinker -headerpad -Xlinker 6C8   \
          -o temacs pre-crt0.o dispnew.o frame.o scroll.o xdisp.o menu.o  
window.o charset.o coding.o category.o ccl.o character.o chartab.o bidi.o cm.o 
term.o terminal.o xfaces.o    emacs.o keyboard.o macros.o keymap.o sysdep.o 
buffer.o filelock.o insdel.o marker.o minibuf.o fileio.o dired.o filemode.o 
cmds.o casetab.o casefiddle.o indent.o search.o regex.o undo.o alloc.o data.o 
doc.o editfns.o callint.o eval.o floatfns.o fns.o font.o print.o lread.o 
syntax.o unexmacosx.o bytecode.o process.o callproc.o region-cache.o sound.o 
atimer.o doprnt.o strftime.o intervals.o textprop.o composite.o md5.o xml.o   
nsterm.o nsfns.o nsmenu.o nsselect.o nsimage.o nsfont.o fontset.o fringe.o 
image.o   terminfo.o lastfile.o      mktime.o         -L/opt/local/lib -lxml2 
-lpthread -lz -liconv -lm    -lresolv  -lncurses           
ld: warning: in /opt/local/lib/libxml2.dylib, file is not of required 
architecture
Undefined symbols:
  "_xmlCleanupParser", referenced from:
      _parse_buffer in xml.o
  "_xmlDocGetRootElement", referenced from:
      _parse_buffer in xml.o
  "_xmlReadMemory", referenced from:
      _parse_buffer in xml.o
  "_htmlReadMemory", referenced from:
      _parse_buffer in xml.o
  "_xmlCheckVersion", referenced from:
      _parse_buffer in xml.o
  "_xmlFreeDoc", referenced from:
      _parse_buffer in xml.o
ld: symbol(s) not found

address@hidden:~/em24.git emacs24$ lipo -info /opt/local/lib/libxml2.dylib
Non-fat file: /opt/local/lib/libxml2.dylib is architecture: i386


Would it be possible to fix the configure script to make sure that the library 
is not only present, but that it can actually be bound?