FreeBSD 4.8 and MacOS X 10.2 have a broken ncurses.h - if you don't
define _XOPEN_EXTENDED_SOURCE, the bug isn't triggered. Testing on
FreeBSD shows that nothing is broken by this change.
diff --git a/configure b/configure
index 53f567c..837f3e8 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 1.436 .
+# From configure.in Revision: 1.437 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.57 for python 2.4.
 #
@@ -1452,6 +1452,12 @@
   # but used in struct sockaddr.sa_family. Reported by Tim Rice.
   SCO_SV/3.2)
     define_xopen_source=no;;
+  # On FreeBSD 4.8 and MacOS X 10.2, a bug in ncurses.h means that
+  # it craps out if _XOPEN_EXTENDED_SOURCE is defined. Apparently,
+  # this is fixed in 10.3, which identifies itself as Darwin/7.*
+  # This should hopefully be fixed in FreeBSD 4.9
+  FreeBSD/4.8* | Darwin/6* )
+    define_xopen_source=no;;
 esac
 
 if test $define_xopen_source = yes