Issue #12196: Add PIPE_MAX_SIZE to test.support, constant larger than the
underlying OS pipe buffer size.
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index c0dc6ec..0ffb4a1 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -2683,7 +2683,7 @@
# The buffered IO layer must check for pending signal
# handlers, which in this case will invoke alarm_interrupt().
self.assertRaises(ZeroDivisionError,
- wio.write, item * (1024 * 1024))
+ wio.write, item * (support.PIPE_MAX_SIZE // len(item)))
t.join()
# We got one byte, get another one and check that it isn't a
# repeat of the first one.