sys.platform on Mac OS X is now "darwin", without any version number appended.
This should probably go into NEWS (who's responsible for that?).
diff --git a/Lib/test/test_fcntl.py b/Lib/test/test_fcntl.py
index e446249..1cb62b5 100755
--- a/Lib/test/test_fcntl.py
+++ b/Lib/test/test_fcntl.py
@@ -16,7 +16,7 @@
 else:
     start_len = "qq"
 
-if sys.platform in ('netbsd1', 'Darwin1.2', 'darwin1',
+if sys.platform in ('netbsd1', 'Darwin1.2', 'darwin',
                     'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
                     'bsdos2', 'bsdos3', 'bsdos4',
                     'openbsd', 'openbsd2'):