The C function used by uuid.uuid4 is broken on
OSX 10.6 in that after os.fork() the parent and
child generate the same sequence of UUIDs.

This patch falls back to the the Python implementation
on OSX 10.6 or later.

Fixes issue #8621.
diff --git a/Misc/NEWS b/Misc/NEWS
index f672f4a..52fd276 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -39,6 +39,9 @@
 Library
 -------
 
+- Issue #8621: uuid.uuid4() returned the same sequence of values in the
+  parent and any children created using ``os.fork`` on MacOS X 10.6.
+
 - Issue #8313: traceback.format_exception_only() encodes unicode message to
   ASCII with backslashreplace error handler if str(value) failed