Use pytest.ini to reduce EncodingWarning spam

pytest.ini

@@ -9,25 +9,36 @@ filterwarnings=
 	# Fail on warnings
 	error
 
+	# Workarounds for pypa/setuptools#3810
+	# Can't use EncodingWarning as it doesn't exist on Python 3.9.
+	# These warnings only appear on Python 3.10+
+	default:'encoding' argument not specified
+	# Until Python 3.9 support is dropped, we can't use `encoding="locale"` directly,
+	# but we'd also prefer switching to `encoding="utf-8"` wherever possible
+	# in preparation of https://peps.python.org/pep-0686/
+	# In the mean time, it causes too much noise in tests
+	ignore:'encoding' argument not specified::setuptools
+	ignore:'encoding' argument not specified::pkg_resources
+
 	## upstream
 
 	# Ensure ResourceWarnings are emitted
 	default::ResourceWarning
 
+	# subprocess.check_output still warns with EncodingWarning even with encoding set
+	ignore:'encoding' argument not specified::setuptools.tests.environment
+
 	# realpython/pytest-mypy#152
 	ignore:'encoding' argument not specified::pytest_mypy
 
-	# python/cpython#100750
-	ignore:'encoding' argument not specified::platform
-
-	# pypa/build#615
-	ignore:'encoding' argument not specified::build.env
-
-	# dateutil/dateutil#1284
-	ignore:datetime.datetime.utcfromtimestamp:DeprecationWarning:dateutil.tz.tz
+	# pytest-dev/pytest # TODO: Raise issue upstream 
+	ignore:'encoding' argument not specified::_pytest
 
 	## end upstream
 
+	# pypa/distutils#236
+	ignore:'encoding' argument not specified::distutils
+
 	# https://github.com/pypa/setuptools/issues/1823
 	ignore:bdist_wininst command is deprecated
 	# Suppress this error; unimportant for CI tests
@@ -68,11 +79,6 @@ filterwarnings=
 	# https://github.com/pypa/setuptools/issues/3655
 	ignore:The --rsyncdir command line argument and rsyncdirs config variable are deprecated.:DeprecationWarning
 
-	# Workarounds for pypa/setuptools#3810
-	# Can't use EncodingWarning as it doesn't exist on Python 3.9
-	default:'encoding' argument not specified
-	default:UTF-8 Mode affects locale.getpreferredencoding().
-
 	# Avoid errors when testing pkg_resources.declare_namespace
 	ignore:.*pkg_resources\.declare_namespace.*:DeprecationWarning
 

setuptools/command/editable_wheel.py

@@ -538,7 +538,8 @@ def _encode_pth(content: str) -> bytes:
     This function tries to simulate this behaviour without having to create an
     actual file, in a way that supports a range of active Python versions.
     (There seems to be some variety in the way different version of Python handle
-    ``encoding=None``, not all of them use ``locale.getpreferredencoding(False)``).
+    ``encoding=None``, not all of them use ``locale.getpreferredencoding(False)``
+    or ``locale.getencoding()``).
     """
     encoding = "locale" if sys.version_info >= (3, 10) else None
     with io.BytesIO() as buffer:

setuptools/tests/__init__.py

@@ -1,10 +1,15 @@
 import locale
+import sys
 
 import pytest
 
 
 __all__ = ['fail_on_ascii']
 
-
-is_ascii = locale.getpreferredencoding() == 'ANSI_X3.4-1968'
+locale_encoding = (
+    locale.getencoding()
+    if sys.version_info >= (3, 11)
+    else locale.getpreferredencoding(False)
+)
+is_ascii = locale_encoding == 'ANSI_X3.4-1968'
 fail_on_ascii = pytest.mark.xfail(is_ascii, reason="Test fails in this locale")