Sync pre-release CPython 3.15 branch from GitHub (2026-10-06)

Summary:
Imported python/cpython `3.15.0rc3+dev` from upstream rev [`6fae227`](https://www.github.com/python/cpython/commit/6fae227c51f4457796c9e9f4088efe8c0a517682) (committed 2026-10-06 13:47:00+00:00).

# Commit Info

- Base: (`3.15.0rc3+dev`) - [`c49b3dc`](https://www.github.com/python/cpython/commit/c49b3dc3cdd0ec20aeee697a5bc37c634b5f2820) (commit date: 2026-10-05 17:15:41+00:00)
- Imported: (`3.15.0rc3+dev`) - [`6fae227`](https://www.github.com/python/cpython/commit/6fae227c51f4457796c9e9f4088efe8c0a517682) (commit date: 2026-10-06 13:47:00+00:00)

Differential Revision: D123805300

fbshipit-source-id: 726b4dbfc7081db1f6c8192c486729c78f30677b

Author: generatedunixname1734921407115435

Doc/howto/abi3t-migration.rst

@@ -217,9 +217,9 @@ Module export hook
 
 Unless you've done this step already, your extension module defines a
 :ref:`module initialization function <extension-pyinit>`
-named :samp:`PyInit_{<module_name>}`.
+named :samp:`PyInit_{<modname>}` (where ``modname`` is the name of your module).
 You will need to port it to a :ref:`module export hook <extension-export-hook>`,
-:samp:`PyModExport_{<module name>}`, a feature added in CPython 3.15 in
+:samp:`PyModExport_{<modname>}`, a feature added in CPython 3.15 in
 :pep:`793`.
 
 Your existing init function should look like this (with your own names
@@ -297,6 +297,34 @@ pointer to static data.
 If you cannot avoid additional code, refer to the
 :ref:`caveats in PyModExport documentation <pymodexport-api-caveats>`.
 
+.. note::
+
+   When building for Windows using the Setuptools_ build tool,
+   removing the :samp:`PyInit_{<modname>}` function may result in the linker error
+   :samp:`LINK : error LNK2001: unresolved external symbol PyInit_{<modname>}`.
+   This is caused by Setuptools passing an ``/EXPORT`` linker flag, which
+   is redundant since Python 3.15 (see :gh:`141671`).
+   A workaround is to add a dummy :samp:`PyInit_{<modname>}` function
+   to your code.
+   Python 3.15+ will never call this function if
+   :samp:`PyModExport_{<modname>}` is present, so it can always fail:
+
+   .. code-block:: c
+
+      // Workaround for https://github.com/pypa/distutils/issues/387
+      PyMODINIT_FUNC
+      PyInit_<modname>(void)
+      {
+          PyErr_SetString(PyExc_SystemError,
+                          "PyInit_* called for module with PyModExport_*");
+          return NULL;
+      }
+
+   (This issue is present in Setuptools 84.0.0; it might be fixed in newer
+   versions.)
+
+.. _Setuptools: https://setuptools.pypa.io/
+
 
 Existing slots
 --------------

Lib/test/test_android.py

@@ -1,4 +1,5 @@
 import io
+import platform
 import queue
 import re
 import subprocess
@@ -16,6 +17,11 @@
 if sys.platform != "android":
     raise unittest.SkipTest("Android-specific")
 
+# Some API levels filter out consecutive identical lines and replace them with a
+# "chatty" marker.
+api_level = platform.android_ver().api_level
+chatty_issue = (26 <= api_level <= 30)
+
 # (name, level, fileno)
 STREAM_INFO = [("stdout", "I", 1), ("stderr", "W", 2)]
 
@@ -174,15 +180,13 @@ def write(s, lines=None, *, write_len=None):
                     write("\u0000b", [r"\xc0\x80b"])
                     write("a\u0000b", [r"a\xc0\x80b"])
 
-                # Multi-line messages. Avoid identical consecutive lines, as
-                # they may activate "chatty" filtering and break the tests.
-                #
-                # Additional spaces will appear in the output where necessary to
-                # protect leading newlines.
+                # Multi-line messages. Additional spaces will appear in the output where
+                # necessary to protect leading newlines.
                 write("\nx", [" "])
                 write("\na\n", ["x", "a"])
                 write("\n", [" "])
-                write("\n\n", [" ", " "])
+                if not chatty_issue:
+                    write("\n\n", [" ", " "])
                 write("b\n", ["b"])
                 write("c\n\n", ["c", " "])
                 write("d\ne", ["d"])
@@ -201,7 +205,8 @@ def write(s, lines=None, *, write_len=None):
                     write("\nx", [" ", "x"])
                     write("\na\n", [" ", "a"])
                     write("\n", [" "])
-                    write("\n\n", [" ", " "])
+                    if not chatty_issue:
+                        write("\n\n", [" ", " "])
                     write("b\n", ["b"])
                     write("c\n\n", ["c", " "])
                     write("d\ne", ["d", "e"])