From b35394aca15a51ff6fb44943c9f9530c68e685c4 Mon Sep 17 00:00:00 2001
From: Julien Palard <julien@palard.fr>
Date: Tue, 27 Sep 2022 15:56:47 +0200
Subject: [PATCH 1/3] expand: Give bytes to ast.parse to let it discover
 encoding cookie.

---
 setuptools/config/expand.py            |  2 +-
 setuptools/tests/config/test_expand.py | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/setuptools/config/expand.py b/setuptools/config/expand.py
index 384504d879..693b2dbc30 100644
--- a/setuptools/config/expand.py
+++ b/setuptools/config/expand.py
@@ -62,7 +62,7 @@ class StaticModule:
     """Proxy to a module object that avoids executing arbitrary code."""
 
     def __init__(self, name: str, spec: ModuleSpec):
-        with open(spec.origin) as strm:  # type: ignore
+        with open(spec.origin, mode='rb') as strm:  # type: ignore
             src = strm.read()
         module = ast.parse(src)
         vars(self).update(locals())
diff --git a/setuptools/tests/config/test_expand.py b/setuptools/tests/config/test_expand.py
index 523779a8ed..39f3b7c70f 100644
--- a/setuptools/tests/config/test_expand.py
+++ b/setuptools/tests/config/test_expand.py
@@ -60,6 +60,20 @@ def test_read_files(tmp_path, monkeypatch):
 
 
 class TestReadAttr:
+    @pytest.mark.parametrize(
+        "example",
+        [
+            # No cookie means UTF-8:
+            b"__version__ = '\xc3\xa9'\nraise SystemExit(1)\n",
+            # If a cookie is present, honor it:
+            b"# -*- coding: utf-8 -*-\n__version__ = '\xc3\xa9'\nraise SystemExit(1)\n",
+            b"# -*- coding: latin1 -*-\n__version__ = '\xe9'\nraise SystemExit(1)\n",
+        ]
+    )
+    def test_read_attr_encoding_cookie(self, example, tmp_path):
+        (tmp_path / "mod.py").write_bytes(example)
+        assert expand.read_attr('mod.__version__', root_dir=tmp_path) == 'é'
+
     def test_read_attr(self, tmp_path, monkeypatch):
         files = {
             "pkg/__init__.py": "",

From fb62784d242fdeb38d06c4d1d8277c25775e7fca Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 29 Sep 2022 19:39:22 -0400
Subject: [PATCH 2/3] Use pathlib to open the file

---
 setuptools/config/expand.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/setuptools/config/expand.py b/setuptools/config/expand.py
index 693b2dbc30..38eb3db7d8 100644
--- a/setuptools/config/expand.py
+++ b/setuptools/config/expand.py
@@ -21,6 +21,7 @@
 import importlib
 import io
 import os
+import pathlib
 import sys
 import warnings
 from glob import iglob
@@ -62,9 +63,7 @@ class StaticModule:
     """Proxy to a module object that avoids executing arbitrary code."""
 
     def __init__(self, name: str, spec: ModuleSpec):
-        with open(spec.origin, mode='rb') as strm:  # type: ignore
-            src = strm.read()
-        module = ast.parse(src)
+        module = ast.parse(pathlib.Path(spec.origin).read_bytes())
         vars(self).update(locals())
         del self.self
 

From 80cce711a61f44357c04c5ce79d1f02ae6c321c6 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 29 Sep 2022 19:43:31 -0400
Subject: [PATCH 3/3] Update changelog

---
 changelog.d/3613.misc.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/3613.misc.rst

diff --git a/changelog.d/3613.misc.rst b/changelog.d/3613.misc.rst
new file mode 100644
index 0000000000..7e64ed46aa
--- /dev/null
+++ b/changelog.d/3613.misc.rst
@@ -0,0 +1 @@
+Fixed encoding errors in ``expand.StaticModule`` when system default encoding doesn't match expectations for source files.