EncodingWarnings in configuration.py and utils/subprocess.py

[bluetech]

Description

Some projects I'm working on (e.g. black, pytest) have started setting PYTHONWARNDEFAULTENCODING=1 in their tox configurations (see PEP 597 – Add optional EncodingWarning). It affects pip as well, and pip is not clean from these warnings:

black/.tox/py311/lib/python3.11/site-packages/pip/_internal/configuration.py:284: EncodingWarning: UTF-8 Mode affects locale.getpreferredencoding(). Consider locale.getencoding() instead.
  locale_encoding = locale.getpreferredencoding(False)
black/.tox/py311/lib/python3.11/site-packages/pip/_internal/configuration.py:284: EncodingWarning: UTF-8 Mode affects locale.getpreferredencoding(). Consider locale.getencoding() instead.
  locale_encoding = locale.getpreferredencoding(False)
Obtaining file:///home/ran/src/black
black/.tox/py311/lib/python3.11/site-packages/pip/_internal/utils/subprocess.py:141: EncodingWarning: 'encoding' argument not specified.
  proc = subprocess.Popen(

The "Consider locale.getencoding() instead" warning is explained by PEP 686 – Make UTF-8 mode default.

Expected behavior

No warnings under PYTHONWARNDEFAULTENCODING=1.

pip version

23.2.1

Python version

3.11

OS

Linux

How to Reproduce

Running PYTHONWARNDEFAULTENCODING=1 pip is sufficient for the first two warnings.

The subprocess warning I get when doing PYTHONWARNDEFAULTENCODING=1 pip install -e . in black repo (trying to mimic what tox does).

Output

No response

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[notatallshaw]

I beleive this is a duplicate of #10590?

Unless there's something extra about the subprocess?

[bluetech]

If I understand correctly, the warnings reported in #10590 were fixed in #10593. The subprocess warning is maybe new or was missed. And the UTF-8 Mode warnings I believe didn't exist back then.

[Avasam]

The utils/subprocess.py report would be a duplicate of #12070

[jaraco]

Closing as a duplicate of #10590 and #12070.