See also http://finkproject.org/doc/porting/libtool.php
(Section 3.3) Fixing 1.4.x (Subsection 1) The flat_namespace bug
--- configure~	2007-10-08 01:55:00 +0200
+++ configure	2007-10-08 01:55:27 +0200
@@ -3063,9 +3063,6 @@
 
 
 case "${host}" in
-  *-*-darwin*)
-    LINKFLAGS="-no-undefined"
-    ;;
   *)
     if test "$GXX"
     then
@@ -7907,7 +7904,7 @@
     ;;
 
   darwin* | rhapsody*)
-    allow_undefined_flag='-undefined suppress'
+    allow_undefined_flag='-undefined suppress -flat_namespace'
     # FIXME: Relying on posixy $() will cause problems for
     #        cross-compilation, but unfortunately the echo tests do not
     #        yet detect zsh echo's removal of \ escapes.
--- config/ltmain.sh~	2002-01-17 14:45:52 +0100
+++ config/ltmain.sh	2007-10-08 03:08:26 +0200
@@ -3913,10 +3913,15 @@
 
 # Directory that this library needs to be installed in:
 libdir='$install_libdir'"
+case "${host}" in
+  *-*-darwin*)
+    ;;
+  *)
 	  if test "$installed" = no && test $need_relink = yes; then
 	    $echo >> $output "\
 relink_command=\"$relink_command\""
 	  fi
+esac
 	done
       fi