.. bpo: 46070
.. date: 2022-01-13-17-58-56
.. nonce: q8IGth
.. release date: 2022-01-13
.. section: Core and Builtins

:c:func:`Py_EndInterpreter` now explicitly untracks all objects currently
tracked by the GC. Previously, if an object was used later by another
interpreter, calling :c:func:`PyObject_GC_UnTrack` on the object crashed if
the previous or the next object of the :c:type:`PyGC_Head` structure became
a dangling pointer. Patch by Victor Stinner.

..

.. bpo: 46085
.. date: 2021-12-30-00-23-41
.. nonce: bDuJqu
.. section: Core and Builtins

Fix iterator cache mechanism of :class:`OrderedDict`.

..

.. bpo: 46110
.. date: 2021-12-18-02-37-07
.. nonce: B6hAfu
.. section: Core and Builtins

Add a maximum recursion check to the PEG parser to avoid stack overflow.
Patch by Pablo Galindo

..

.. bpo: 46000
.. date: 2021-12-07-11-42-44
.. nonce: v_ru3k
.. section: Core and Builtins

Improve compatibility of the :mod:`curses` module with NetBSD curses.

..

.. bpo: 45614
.. date: 2021-11-23-12-06-41
.. nonce: fIekgI
.. section: Core and Builtins

Fix :mod:`traceback` display for exceptions with invalid module name.

..

.. bpo: 45806
.. date: 2021-11-19-19-21-48
.. nonce: DflDMe
.. section: Core and Builtins

Re-introduced fix that allows recovery from stack overflow without crashing
the interpreter.  The original fix as part of :issue:`42500` was reverted
(see release notes for Python 3.9.4) since it introduced an ABI change in a
bugfix release which is not allowed.  The new fix doesn't introduce any ABI
changes.  Patch by Mark Shannon.

..

.. bpo: 45822
.. date: 2021-11-16-19-41-04
.. nonce: OT6ueS
.. section: Core and Builtins

Fixed a bug in the parser that was causing it to not respect :pep:`263`
coding cookies when no flags are provided. Patch by Pablo Galindo

..

.. bpo: 45820
.. date: 2021-11-16-19-00-27
.. nonce: 2X6Psr
.. section: Core and Builtins

Fix a segfault when the parser fails without reading any input. Patch by
Pablo Galindo

..

.. bpo: 42540
.. date: 2021-11-15-12-08-27
.. nonce: V2w107
.. section: Core and Builtins

Fix crash when :func:`os.fork` is called with an active non-default memory
allocator.

..

.. bpo: 40479
.. date: 2022-01-07-15-20-19
.. nonce: EKfr3F
.. section: Library

Fix :mod:`hashlib` *usedforsecurity* option to work correctly with OpenSSL
3.0.0 in FIPS mode.

..

.. bpo: 46070
.. date: 2022-01-07-13-51-22
.. nonce: -axLUW
.. section: Library

Fix possible segfault when importing the :mod:`asyncio` module from
different sub-interpreters in parallel. Patch by Erlend E. Aasland.

..

.. bpo: 46278
.. date: 2022-01-06-13-38-00
.. nonce: wILA80
.. section: Library

Reflect ``context`` argument in ``AbstractEventLoop.call_*()`` methods. Loop
implementations already support it.

..

.. bpo: 46239
.. date: 2022-01-03-12-59-20
.. nonce: ySVSEy
.. section: Library

Improve error message when importing :mod:`asyncio.windows_events` on
non-Windows.

..

.. bpo: 20369
.. date: 2021-12-17-12-06-40
.. nonce: zzLuBz
.. section: Library

:func:`concurrent.futures.wait` no longer blocks forever when given
duplicate Futures. Patch by Kumar Aditya.

..

.. bpo: 46105
.. date: 2021-12-16-14-30-36
.. nonce: pprB1K
.. section: Library

Honor spec when generating requirement specs with urls and extras
(importlib_metadata 4.8.3).

..

.. bpo: 26952
.. date: 2021-12-14-13-18-45
.. nonce: hjhISq
.. section: Library

:mod:`argparse` raises :exc:`ValueError` with clear message when trying to
render usage for an empty mutually-exclusive group. Previously it raised a
cryptic :exc:`IndexError`.

..

.. bpo: 27718
.. date: 2021-12-11-22-51-30
.. nonce: MgQiGl
.. section: Library

Fix help for the :mod:`signal` module. Some functions (e.g. ``signal()`` and
``getsignal()``) were omitted.

..

.. bpo: 46032
.. date: 2021-12-11-15-45-07
.. nonce: HmciLT
.. section: Library

The ``registry()`` method of :func:`functools.singledispatch` functions
checks now the first argument or the first parameter annotation and raises a
TypeError if it is not supported. Previously unsupported "types" were
ignored (e.g. ``typing.List[int]``) or caused an error at calling time (e.g.
``list[int]``).

..

.. bpo: 46018
.. date: 2021-12-09-00-44-42
.. nonce: hkTI7v
.. section: Library

Ensure that :func:`math.expm1` does not raise on underflow.

..

.. bpo: 27946
.. date: 2021-12-04-20-08-42
.. nonce: -Vuarf
.. section: Library

Fix possible crash when getting an attribute of
class:`xml.etree.ElementTree.Element` simultaneously with replacing the
``attrib`` dict.

..

.. bpo: 13236
.. date: 2021-11-30-13-52-02
.. nonce: FmJIkO
.. section: Library

:class:`unittest.TextTestResult` and :class:`unittest.TextTestRunner` flush
now the output stream more often.

..

.. bpo: 37658
.. date: 2021-11-28-15-30-34
.. nonce: 8Hno7d
.. section: Library

Fix issue when on certain conditions ``asyncio.wait_for()`` may allow a
coroutine to complete successfully, but fail to return the result,
potentially causing memory leaks or other issues.

..

.. bpo: 45831
.. date: 2021-11-17-19-25-37
.. nonce: 9-TojK
.. section: Library

:mod:`faulthandler` can now write ASCII-only strings (like filenames and
function names) with a single write() syscall when dumping a traceback. It
reduces the risk of getting an unreadable dump when two threads or two
processes dump a traceback to the same file (like stderr) at the same time.
Patch by Victor Stinner.

..

.. bpo: 41735
.. date: 2021-11-17-11-38-30
.. nonce: 2feh9v
.. section: Library

Fix thread lock in ``zlib.Decompress.flush()`` method before
``PyObject_GetBuffer``.

..

.. bpo: 45664
.. date: 2021-10-28-23-40-54
.. nonce: 7dqtxQ
.. section: Library

Fix :func:`types.resolve_bases` and :func:`types.new_class` for
:class:`types.GenericAlias` instance as a base.

..

.. bpo: 45663
.. date: 2021-10-28-23-11-59
.. nonce: J90N5R
.. section: Library

Fix :func:`dataclasses.is_dataclass` for dataclasses which are subclasses of
:class:`types.GenericAlias`.

..

.. bpo: 45662
.. date: 2021-10-28-22-58-14
.. nonce: sJd7Ir
.. section: Library

Fix the repr of :data:`dataclasses.InitVar` with a type alias to the
built-in class, e.g. ``InitVar[list[int]]``.

..

.. bpo: 43498
.. date: 2021-04-20-14-14-16
.. nonce: L_Hq-8
.. section: Library

Avoid a possible *"RuntimeError: dictionary changed size during iteration"*
when adjusting the process count of :class:`ProcessPoolExecutor`.

..

.. bpo: 29620
.. date: 2018-08-21-16-20-33
.. nonce: xxx666
.. section: Library

:func:`~unittest.TestCase.assertWarns` no longer raises a
``RuntimeException`` when accessing a module's ``__warningregistry__``
causes importation of a new module, or when a new module is imported in
another thread. Patch by Kernc.

..

.. bpo: 19737
.. date: 2021-11-28-22-43-21
.. nonce: cOOubB
.. section: Documentation

Update the documentation for the :func:`globals` function.

..

.. bpo: 45840
.. date: 2021-11-19-02-02-32
.. nonce: A51B2S
.. section: Documentation

Improve cross-references in the documentation for the data model.

..

.. bpo: 45788
.. date: 2021-11-18-00-07-40
.. nonce: qibUoB
.. section: Documentation

Link doc for sys.prefix to sysconfig doc on installation paths.

..

.. bpo: 25381
.. date: 2021-06-21-17-51-51
.. nonce: 7Kn-_H
.. section: Documentation

In the extending chapter of the extending doc, update a paragraph about the
global variables containing exception information.

..

.. bpo: 43905
.. date: 2021-05-24-05-00-12
.. nonce: tBIndE
.. section: Documentation

Expanded :func:`~dataclasses.astuple` and :func:`~dataclasses.asdict` docs,
warning about deepcopy being applied and providing a workaround.

..

.. bpo: 41028
.. date: 2020-06-18-23-37-03
.. nonce: vM8bC8
.. section: Documentation

Language and version switchers, previously maintained in every cpython
branches, are now handled by docsbuild-script.

..

.. bpo: 46205
.. date: 2022-01-07-14-06-12
.. nonce: dnc2OC
.. section: Tests

Fix hang in runtest_mp due to race condition

..

.. bpo: 46263
.. date: 2022-01-06-15-45-34
.. nonce: bJXek6
.. section: Tests

Fix test_capi on FreeBSD 14-dev: instruct jemalloc to not fill freed memory
with junk byte.

..

.. bpo: 46150
.. date: 2021-12-23-13-42-15
.. nonce: RhtADs
.. section: Tests

Now ``fakename`` in ``test_pathlib.PosixPathTest.test_expanduser`` is
checked to be non-existent.

..

.. bpo: 46129
.. date: 2021-12-19-12-20-57
.. nonce: I3MunH
.. section: Tests

Rewrite ``asyncio.locks`` tests with
:class:`unittest.IsolatedAsyncioTestCase` usage.

..

.. bpo: 23819
.. date: 2021-12-19-08-44-32
.. nonce: 9ueiII
.. section: Tests

Fixed :mod:`asyncio` tests in python optimized mode. Patch by Kumar Aditya.

..

.. bpo: 46114
.. date: 2021-12-17-14-46-19
.. nonce: 9iyZ_9
.. section: Tests

Fix test case for OpenSSL 3.0.1 version. OpenSSL 3.0 uses ``0xMNN00PP0L``.

..

.. bpo: 19460
.. date: 2021-11-28-15-25-02
.. nonce: lr0aWs
.. section: Tests

Add new Test for :class:`email.mime.nonmultipart.MIMENonMultipart`.

..

.. bpo: 45835
.. date: 2021-11-17-14-28-08
.. nonce: Mgyhjx
.. section: Tests

Fix race condition in test_queue tests with multiple "feeder" threads.

..

.. bpo: 46263
.. date: 2022-01-05-02-58-10
.. nonce: xiv8NU
.. section: Build

``configure`` no longer sets ``MULTIARCH`` on FreeBSD platforms.

..

.. bpo: 46106
.. date: 2021-12-20-07-10-41
.. nonce: 5qcv3L
.. section: Build

Updated OpenSSL to 1.1.1m in Windows builds, macOS installer builds, and CI.
Patch by Kumar Aditya.

..

.. bpo: 44035
.. date: 2021-12-06-09-31-27
.. nonce: BiO4XC
.. section: Build

CI now verifies that autoconf files have been regenerated with a current and
unpatched autoconf package.

..

.. bpo: 33393
.. date: 2021-11-25-20-26-06
.. nonce: 24YNtM
.. section: Build

Update ``config.guess`` to 2021-06-03 and ``config.sub`` to 2021-08-14.
``Makefile`` now has an ``update-config`` target to make updating more
convenient.

..

.. bpo: 45866
.. date: 2021-11-25-13-53-36
.. nonce: ZH1W8N
.. section: Build

``make regen-all`` now produces the same output when run from a directory
other than the source tree: when building Python out of the source tree.
pegen now strips directory of the "generated by pygen from <FILENAME>"
header Patch by Victor Stinner.

..

.. bpo: 41498
.. date: 2021-11-25-09-15-04
.. nonce: qAk5eo
.. section: Build

Python now compiles on platforms without ``sigset_t``. Several functions in
:mod:`signal` are not available when ``sigset_t`` is missing.

Based on patch by Roman Yurchak for pyodide.

..

.. bpo: 45881
.. date: 2021-11-24-17-14-06
.. nonce: GTXXLk
.. section: Build

``setup.py`` now uses ``CC`` from environment first to discover multiarch
and cross compile paths.

..

.. bpo: 45901
.. date: 2021-11-26-18-17-41
.. nonce: c5IBqM
.. section: Windows

When installed through the Microsoft Store and set as the default app for
:file:`*.py` files, command line arguments will now be passed to Python when
invoking a script without explicitly launching Python (that is, ``script.py
args`` rather than ``python script.py args``).

..

.. bpo: 40477
.. date: 2022-01-02-21-56-53
.. nonce: W3nnM6
.. section: macOS

The Python Launcher app for macOS now properly launches scripts and, if
necessary, the Terminal app when running on recent macOS releases.

..

.. bpo: 45732
.. date: 2021-12-05-23-52-03
.. nonce: -BWrnh
.. section: macOS

Update python.org macOS installer to use Tcl/Tk 8.6.12.

..

.. bpo: 45838
.. date: 2021-11-18-11-20-21
.. nonce: TH6mwc
.. section: Tools/Demos

Fix line number calculation when debugging Python with GDB.

..

.. bpo: 39026
.. date: 2021-11-09-15-42-11
.. nonce: sUnYWn
.. section: C API

Fix Python.h to build C extensions with Xcode: remove a relative include
from ``Include/cpython/pystate.h``.