bpo-45052: Unskips a failing test_shared_memory_basics test

[sobolevn]

https://bugs.python.org/issue45052

[miss-islington]

Thanks @sobolevn for the PR, and @zooba for merging it 🌮🎉.. I'm working now to backport this PR to: 3.9, 3.10.
🐍🍒⛏🤖

[miss-islington]

Sorry, @sobolevn and @zooba, I could not cleanly backport this to 3.9 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 19871fce3b74fc3f37e334a999e00d0ef65a8f1e 3.9

[bedevere-bot]

GH-28185 is a backport of this pull request to the 3.10 branch.

[zooba]

This change doesn't seem to apply to 3.9

[pablogsal]

This seem to have caused several errors that have manifested on the release of 3.10.0rc2:

test test_multiprocessing_fork failed -- Traceback (most recent call last):
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1239, in _dot_lookup
    return getattr(thing, comp)
AttributeError: module 'multiprocessing' has no attribute 'shared_memory'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/test/_test_multiprocessing.py", line 3818, in test_shared_memory_basics
    with unittest.mock.patch(
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1422, in __enter__
    self.target = self.getter()
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1609, in <lambda>
    getter = lambda: _importer(target)
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1252, in _importer
    thing = _dot_lookup(thing, comp, import_path)
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1242, in _dot_lookup
    return getattr(thing, comp)
AttributeError: module 'multiprocessing' has no attribute 'shared_memory'

0:09:11 load avg: 0.71 [231/427/1] test_multiprocessing_forkserver -- test_multiprocessing_fork failed (1 error) in 1 min 11 sec
test test_multiprocessing_forkserver failed -- Traceback (most recent call last):
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1239, in _dot_lookup
    return getattr(thing, comp)
AttributeError: module 'multiprocessing' has no attribute 'shared_memory'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/test/_test_multiprocessing.py", line 3818, in test_shared_memory_basics
    with unittest.mock.patch(
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1422, in __enter__
    self.target = self.getter()
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1609, in <lambda>
    getter = lambda: _importer(target)
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1252, in _importer
    thing = _dot_lookup(thing, comp, import_path)
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1242, in _dot_lookup
    return getattr(thing, comp)
AttributeError: module 'multiprocessing' has no attribute 'shared_memory'

0:11:11 load avg: 0.93 [232/427/2] test_multiprocessing_main_handling -- test_multiprocessing_forkserver failed (1 error) in 2 min
0:11:18 load avg: 1.09 [233/427/2] test_multiprocessing_spawn
test test_multiprocessing_spawn failed -- Traceback (most recent call last):
  File "/tmp/tmpu30qfjpr/installation/lib/python3.10/unittest/mock.py", line 1239, in _dot_lookup
    return getattr(thing, comp)
AttributeError: module 'multiprocessing' has no attribute 'shared_memory'

[sobolevn]

@pablogsal is there a bpo entry for this bug? This test can contain additional problems, this is not a surprise 😞

[pablogsal]

@pablogsal is there a bpo entry for this bug? This test can contain additional problems, this is not a surprise

Not for now, I am trying to debug it, but this is literally blocking the rc2 release of Python 3.10

[sobolevn]

I am sorry! 🙏
Too bad that all checks have passed both for main and 3.10

The easiest (and the fastest) thing is to ignore this test back, but on all platforms, not just windows.
It was ignored for several years (~2), before my change. I will fix it later.

Does this solution seem ok?

[pablogsal]

Does this solution seem ok?

Hummm, it has to be something extra because this is failing currently on Linux. I still prefer to investigate.

I am sorry!

Don't worry, is not your fault :) Nobody knows what's happening, I just know that I cannot release the new rc with these problems.

[pablogsal]

Maybe this is actually due to bpo-45042, who knows

[pablogsal]

Opened https://bugs.python.org/issue45128