Backport 60342:

Try to prevent this test from being flaky.  We might need a sleep in here
which isn't as bad as it sounds.  The close() *should* raise an exception,
so if it didn't we should give more time to sync and really raise it.

Lib/test/test_resource.py

@@ -37,8 +37,11 @@ try:
         f.write("Y")
         f.flush()
         # On some systems (e.g., Ubuntu on hppa) the flush()
-        # doesn't cause the exception, but the close() does.
+        # doesn't always cause the exception, but the close()
-        f.close()
+        # does eventually.  Try closing several times in an attempt
+        # to ensure the file is really synced and the exception raised.
+        for i in range(5):
+            f.close()
     except IOError:
         if not limit_set:
             raise