gh-104522: Fix OSError raised when run a subprocess

[serhiy-storchaka]

Only set filename to cwd if it was caused by failed chdir(cwd).

_fork_exec() now returns "noexec:chdir" for failed chdir(cwd).

Based on idea from #104851. It is more reliable, because does not guess, but know if the error was caused by chdir(cwd). It also contains tests.

• Issue: subprocess raises misleading exceptions from child failure pre-exec #104522

[gpshead]

nice user experience improvement bugfix!

[miss-islington-app]

Thanks @serhiy-storchaka for the PR, and @gpshead for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[miss-islington-app]

Sorry, @serhiy-storchaka and @gpshead, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker e2c097ebdee447ded1109f99a235e65aa3533bf8 3.11

[bedevere-app]

GH-114219 is a backport of this pull request to the 3.12 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.12 has failed when building commit f8fc853.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/1102/builds/605) and take a look at the build logs.
4. Check if the failure is related to this commit (f8fc853) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/1102/builds/605

Failed tests:

• test_subprocess

Failed subtests:

• test_user - test.test_subprocess.POSIXProcessTestCase.test_user

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/test/test_subprocess.py", line 2030, in test_user
    output = subprocess.check_output(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/subprocess.py", line 466, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/subprocess.py", line 548, in run
    with Popen(*popenargs, **kwargs) as process:
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/subprocess.py", line 1026, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/subprocess.py", line 1953, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: '/root/buildarea/3.12.angelico-debian-amd64/build/python'


Traceback (most recent call last):
  File "/root/buildarea/3.12.angelico-debian-amd64/build/Lib/test/test_subprocess.py", line 2036, in test_user
    self.assertIsNone(e.filename)
AssertionError: '/root/buildarea/3.12.angelico-debian-amd64/build/python' is not None

[bedevere-app]

GH-114243 is a backport of this pull request to the 3.11 branch.