Merge pull request #2777 from plumdog/do-not-error-if-use-2to3-is-false

Do not error if use_2to3 is set to a false value

changelog.d/2777.misc.rst

@@ -0,0 +1 @@
+Build does not fail fast when ``use_2to3`` is supplied but set to a false value.

setup.cfg

@@ -124,7 +124,7 @@ distutils.setup_keywords =
 	dependency_links = setuptools.dist:assert_string_list
 	test_loader = setuptools.dist:check_importable
 	test_runner = setuptools.dist:check_importable
-	use_2to3 = setuptools.dist:invalid
+	use_2to3 = setuptools.dist:invalid_unless_false
 egg_info.writers =
 	PKG-INFO = setuptools.command.egg_info:write_pkg_info
 	requires.txt = setuptools.command.egg_info:write_requirements

setuptools/dist.py

@@ -289,7 +289,10 @@ def assert_bool(dist, attr, value):
         raise DistutilsSetupError(tmpl.format(attr=attr, value=value))
 
 
-def invalid(dist, attr, value):
+def invalid_unless_false(dist, attr, value):
+    if not value:
+        warnings.warn(f"{attr} is ignored.", DistDeprecationWarning)
+        return
     raise DistutilsSetupError(f"{attr} is invalid.")