[Python-checkins] Add a comment about how to fix bogus test_host_resolution_bad_address failures (#29085)

[warsaw]

https://github.com/python/cpython/commit/6ef4507c74106884e6c8847f08d004511c4f1197
commit: 6ef4507c74106884e6c8847f08d004511c4f1197
branch: main
author: Barry Warsaw <barry at python.org>
committer: warsaw <barry at python.org>
date: 2021-10-20T08:08:57-07:00
summary:

Add a comment about how to fix bogus test_host_resolution_bad_address failures (#29085)

files:
M Lib/test/test_socket.py

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index eeb8e8c98a149..394d2942483fb 100755
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1017,8 +1017,10 @@ def test_host_resolution(self):
 
     def test_host_resolution_bad_address(self):
         # These are all malformed IP addresses and expected not to resolve to
-        # any result.  But some ISPs, e.g. AWS, may successfully resolve these
-        # IPs.
+        # any result.  But some ISPs, e.g. AWS and AT&T, may successfully
+        # resolve these IPs. In particular, AT&T's DNS Error Assist service
+        # will break this test.  See https://bugs.python.org/issue42092 for a
+        # workaround.
         explanation = (
             "resolving an invalid IP address did not raise OSError; "
             "can be caused by a broken DNS server"