Some tests in test_smtplib and test_logging failed when Python is configured with `--disable-ipv6`

[aisk]

Bug report

Bug description:

There is a error sample:

ERROR: test_basic (test.test_logging.SMTPHandlerTest.test_basic)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/asaka/Codes/cpython/Lib/test/test_logging.py", line 1121, in test_basic
    server = TestSMTPServer((socket_helper.HOST, 0), self.process_message, 0.001,
                            sockmap)
  File "/home/asaka/Codes/cpython/Lib/test/test_logging.py", line 882, in __init__
    smtpd.SMTPServer.__init__(self, addr, None, map=sockmap,
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                              decode_data=True)
                              ^^^^^^^^^^^^^^^^^
  File "/home/asaka/Codes/cpython/Lib/test/support/smtpd.py", line 641, in __init__
    self.bind(localaddr)
    ~~~~~~~~~^^^^^^^^^^^
  File "/home/asaka/Codes/cpython/Lib/test/support/asyncore.py", line 332, in bind
    return self.socket.bind(addr)
           ~~~~~~~~~~~~~~~~^^^^^^
OSError: bind(): bad family

This is caused by SMTPServer is using socket.getaddrinfo to get the socket family, which also include IPv6 result even if IPv6 support is disabled, and it's value will be used to socket.bind:

cpython/Lib/test/support/smtpd.py

Lines 636 to 638 in 6343486

	gai_results = socket.getaddrinfo(*localaddr,
	type=socket.SOCK_STREAM)
	self.create_socket(gai_results[0][0], gai_results[0][1])

--disable-ipv6 must be specified when --with-thread-sanitizer is specified on my machine (Arch with Clang17), so I think it's better to fix it although --disable-ipv6 is not widely used.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-121275: Fix test_logging and test_smtplib with Python build withoud IPv6 support #121276

[vstinner]

--disable-ipv6 must be specified when --with-thread-sanitizer is specified on my machine (Arch with Clang17)

Would you mind to elaborate?

[aisk]

I didn't dig too much, but ./configure --with-thread-sanitizer on my machine will cause a:

configure: error: You must get working getaddrinfo() function or pass the "--disable-ipv6" option to configure.

Maybe it's caused by google/sanitizers#1592

[vstinner]

Do you want to work on a PR to skip some tests if IPv6 is disabled?

[aisk]

Do you want to work on a PR to skip some tests if IPv6 is disabled?

Working on it.

[aisk]

Hi @vstinner, I found that the following tests will fail when using --disable-ipv6:

• test_smtplib
• test_logging
• test_asyncio.test_events
• test_asyncio.test_streams

The first two can be solved by #121276. For the last two, I think it's not just a bug in the tests, but it could also cause problems in user's code.

[aisk]

Hi @vstinner, I found that the following tests will fail when using --disable-ipv6:

• test_smtplib
• test_logging
• test_asyncio.test_events
• test_asyncio.test_streams

The first two can be solved by #121276. For the last two, I think it's not just a bug in the tests, but it could also cause problems in user's code.

Sorry, I missed an import information for the last sentence:

For the last two, I think it's not just a bug in the tests, but it could also cause problems in user's code, and I created #121913 for the detail and future discussion.