Mention a configure warning that almost certainly indicates that
configure is picking up a library that doesn't contain all architectures
required for a universal build on OSX.
diff --git a/Mac/README b/Mac/README
index afd2173..e4ff868 100644
--- a/Mac/README
+++ b/Mac/README
@@ -217,6 +217,25 @@
from within the BuildScript directory. The script accepts a number of
command-line arguments, run it with --help for more information.
+Configure warnings
+==================
+
+The configure script sometimes emits warnings like the one below::
+
+ configure: WARNING: libintl.h: present but cannot be compiled
+ configure: WARNING: libintl.h: check for missing prerequisite headers?
+ configure: WARNING: libintl.h: see the Autoconf documentation
+ configure: WARNING: libintl.h: section "Present But Cannot Be Compiled"
+ configure: WARNING: libintl.h: proceeding with the preprocessor's result
+ configure: WARNING: libintl.h: in the future, the compiler will take precedence
+ configure: WARNING: ## -------------------------------------- ##
+ configure: WARNING: ## Report this to http://bugs.python.org/ ##
+ configure: WARNING: ## -------------------------------------- ##
+
+This almost always means you are trying to build a universal binary for
+Python and have libaries in ``/usr/local`` that don't contain the required
+architectures. Temporarily move ``/usr/local`` aside to finish the build.
+
Odds and ends
=============