cpython/Misc/NEWS.d/3.11.0a4.rst

.. 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: 46347
.. date: 2022-01-11-13-57-00
.. nonce: Gd8M-S
.. section: Core and Builtins

Fix memory leak in PyEval_EvalCodeEx.

..

.. bpo: 46339
.. date: 2022-01-11-11-50-19
.. nonce: OVumDZ
.. section: Core and Builtins

Fix a crash in the parser when retrieving the error text for multi-line
f-strings expressions that do not start in the first line of the string.
Patch by Pablo Galindo

..

.. bpo: 46331
.. date: 2022-01-10-16-21-54
.. nonce: h1AC-i
.. section: Core and Builtins

Do not set line number of instruction storing doc-string. Fixes regression
introduced in 3.11 alpha.

..

.. bpo: 46314
.. date: 2022-01-10-12-34-17
.. nonce: jId9Ky
.. section: Core and Builtins

Remove spurious "call" event when creating a lambda function that was
accidentally introduced in 3.11a4.

..

.. bpo: 46289
.. date: 2022-01-07-23-32-03
.. nonce: NnjpVc
.. section: Core and Builtins

ASDL declaration of ``FormattedValue`` has changed to reflect ``conversion``
field is not optional.

..

.. bpo: 46297
.. date: 2022-01-07-22-13-59
.. nonce: 83ThTl
.. section: Core and Builtins

Fixed an interpreter crash on bootup with multiple PythonPaths set in the
Windows registry. Patch by Derzsi Dániel.

..

.. bpo: 46237
.. date: 2022-01-07-19-33-05
.. nonce: 9A6Hpq
.. section: Core and Builtins

Fix the line number of tokenizer errors inside f-strings. Patch by Pablo
Galindo.

..

.. bpo: 46263
.. date: 2022-01-06-10-54-07
.. nonce: 60dRZb
.. section: Core and Builtins

We always expect the "use_frozen_modules" config to be set, now that
getpath.c was rewritten in pure Python and the logic improved.

..

.. bpo: 46006
.. date: 2022-01-05-17-13-47
.. nonce: hdH5Vn
.. section: Core and Builtins

Fix a regression when a type method like ``__init__()`` is modified in a
subinterpreter. Fix a regression in ``_PyUnicode_EqualToASCIIId()`` and type
``update_slot()``. Revert the change which made the Unicode dictionary of
interned strings compatible with subinterpreters: the internal interned
dictionary is shared again by all interpreters. Patch by Victor Stinner.

..

.. bpo: 45923
.. date: 2022-01-04-14-08-10
.. nonce: rBp7r1
.. section: Core and Builtins

Add RESUME opcode. This is a logical no-op. It is emitted by the compiler
anywhere a Python function can be entered. It is used by the interpreter to
perform tracing and optimizer checks.

..

.. bpo: 46208
.. date: 2022-01-04-01-53-35
.. nonce: i00Vz5
.. section: Core and Builtins

Fix the regression of os.path.normpath("A/../../B") not returning expected
"../B" but "B".

..

.. bpo: 46240
.. date: 2022-01-03-23-31-25
.. nonce: 8lGjeK
.. section: Core and Builtins

Correct the error message for unclosed parentheses when the tokenizer
doesn't reach the end of the source when the error is reported. Patch by
Pablo Galindo

..

.. bpo: 46009
.. date: 2022-01-03-11-36-34
.. nonce: QZGrov
.. section: Core and Builtins

Remove the ``GEN_START`` opcode.

..

.. bpo: 46235
.. date: 2022-01-02-23-55-13
.. nonce: gUjp2v
.. section: Core and Builtins

Certain sequence multiplication operations like ``[0] * 1_000`` are now
faster due to reference-counting optimizations. Patch by Dennis Sweeney.

..

.. bpo: 46221
.. date: 2022-01-01-14-23-57
.. nonce: 7oGp-I
.. section: Core and Builtins

:opcode:`PREP_RERAISE_STAR` no longer pushes ``lasti`` to the stack.

..

.. bpo: 46202
.. date: 2021-12-30-11-06-27
.. nonce: IKx4v6
.. section: Core and Builtins

Remove :opcode:`POP_EXCEPT_AND_RERAISE` and replace it by an equivalent
sequence of other opcodes.

..

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

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

..

.. bpo: 46055
.. date: 2021-12-24-20-21-45
.. nonce: R0QMVQ
.. section: Core and Builtins

Speed up shifting operation involving integers less than
:c:macro:`PyLong_BASE`. Patch by Xinhang Xu.

..

.. 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: 46107
.. date: 2021-12-16-23-27-05
.. nonce: 7q5an0
.. section: Core and Builtins

Fix bug where :meth:`ExceptionGroup.split` and
:meth:`ExceptionGroup.subgroup` did not copy the exception group's
``__note__`` field to the parts.

..

.. bpo: 45711
.. date: 2021-12-15-15-17-04
.. nonce: QK4QrB
.. section: Core and Builtins

The interpreter state's representation of handled exceptions (a.k.a
exc_info, or _PyErr_StackItem) now has only the ``exc_value`` field,
``exc_type`` and ``exc_traceback`` have been removed as their values can be
derived from ``exc_value``.

..

.. bpo: 44525
.. date: 2021-12-13-17-12-16
.. nonce: 4-FiSf
.. section: Core and Builtins

Replace the four call bytecode instructions which one pre-call instruction
and two call instructions.

Removes ``CALL_FUNCTION``, ``CALL_FUNCTION_KW``, ``CALL_METHOD`` and
``CALL_METHOD_KW``.

Adds ``CALL_NO_KW`` and ``CALL_KW`` call instructions, and
``PRECALL_METHOD`` prefix for pairing with ``LOAD_METHOD``.

..

.. bpo: 46039
.. date: 2021-12-13-17-01-13
.. nonce: TrCBbF
.. section: Core and Builtins

Remove the ``YIELD_FROM`` instruction and replace it with the ``SEND``
instruction which performs the same operation, but without the loop.

..

.. bpo: 45635
.. date: 2021-12-12-15-52-41
.. nonce: ADVaPT
.. section: Core and Builtins

The code called from :c:func:`_PyErr_Display` was refactored to improve
error handling. It now exits immediately upon an unrecoverable error.

..

.. bpo: 46054
.. date: 2021-12-12-05-30-21
.. nonce: 2P-foG
.. section: Core and Builtins

Fix parser error when parsing non-utf8 characters in source files. Patch by
Pablo Galindo.

..

.. bpo: 46042
.. date: 2021-12-11-17-40-34
.. nonce: aqYxku
.. section: Core and Builtins

Improve the location of the caret in :exc:`SyntaxError` exceptions emitted
by the symbol table. Patch by Pablo Galindo.

..

.. bpo: 46049
.. date: 2021-12-11-13-49-19
.. nonce: 9dNto2
.. section: Core and Builtins

Ensure :file:`._pth` files work as intended on platforms other than Windows.

..

.. bpo: 46048
.. date: 2021-12-11-13-14-42
.. nonce: _-OGD9
.. section: Core and Builtins

Fixes parsing of :file:`._pth` files on startup so that single-character
paths are correctly read.

..

.. bpo: 37971
.. date: 2021-12-10-13-42-17
.. nonce: 6BC1Tx
.. section: Core and Builtins

Fix a bug where the line numbers given in a traceback when a decorator
application raised an exception were wrong.

..

.. bpo: 46031
.. date: 2021-12-10-09-10-32
.. nonce: rM7JOX
.. section: Core and Builtins

Add :opcode:`POP_JUMP_IF_NOT_NONE` and :opcode:`POP_JUMP_IF_NONE` opcodes to
speed up conditional jumps.

..

.. bpo: 45654
.. date: 2021-12-09-11-57-43
.. nonce: MZc7ei
.. section: Core and Builtins

Deepfreeze :mod:`runpy`, patch by Kumar Aditya.

..

.. bpo: 46025
.. date: 2021-12-09-11-41-35
.. nonce: pkEvW9
.. section: Core and Builtins

Fix a crash in the :mod:`atexit` module involving functions that unregister
themselves before raising exceptions. 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: 44525
.. date: 2021-12-07-11-04-21
.. nonce: 6OWCgr
.. section: Core and Builtins

Specialize the CALL_FUNCTION instruction for calls to builtin types with a
single argument. Speeds up ``range(x)``, ``list(x)``, and specifically
``type(obj)``.

..

.. bpo: 42918
.. date: 2021-12-06-15-32-12
.. nonce: Czpgtg
.. section: Core and Builtins

Fix bug where the built-in :func:`compile` function did not always raise a
:exc:`SyntaxError` when passed multiple statements in 'single' mode. Patch
by Weipeng Hong.

..

.. bpo: 45953
.. date: 2021-12-01-11-54-27
.. nonce: 2znR0E
.. section: Core and Builtins

The main interpreter in _PyRuntimeState.interpreters is now statically
allocated (as part of _PyRuntime).  Likewise for the initial thread state of
each interpreter.  This means less allocation during runtime init, as well
as better memory locality for these key state objects.

..

.. bpo: 45292
.. date: 2021-11-22-13-05-32
.. nonce: pfEouJ
.. section: Core and Builtins

Complete the :pep:`654` implementation: add ``except*``.

..

.. bpo: 43413
.. date: 2021-05-30-16-37-47
.. nonce: vYFPPC1
.. section: Core and Builtins

Revert changes in ``set.__init__``. Subclass of :class:`set` needs to define
a ``__init__()`` method if it defines a ``__new__()`` method with additional
keyword parameters.

..

.. bpo: 43931
.. date: 2021-04-24-15-39-23
.. nonce: zpChDi
.. section: Core and Builtins

Added the :c:data:`Py_Version` constant which bears the same value as
:c:macro:`PY_VERSION_HEX`. Patch by Gabriele N. Tornetta.

..

.. bpo: 46342
.. date: 2022-01-11-04-28-09
.. nonce: 5QVEH1
.. section: Library

The ``@typing.final`` decorator now sets the ``__final__`` attribute on the
decorated object to allow runtime introspection. Patch by Jelle Zijlstra.

..

.. bpo: 46328
.. date: 2022-01-10-11-53-15
.. nonce: 6i9Wvq
.. section: Library

Added the :meth:`sys.exception` method which returns the active exception
instance.

..

.. bpo: 46307
.. date: 2022-01-10-07-51-43
.. nonce: SKvOIY
.. section: Library

Add :meth:`string.Template.is_valid` and
:meth:`string.Template.get_identifiers` methods.

..

.. bpo: 46306
.. date: 2022-01-08-13-53-25
.. nonce: 1_es8z
.. section: Library

Assume that :class:`types.CodeType` always has
:attr:`types.CodeType.co_firstlineno` in :mod:`doctest`.

..

.. 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: 46244
.. date: 2022-01-06-21-31-14
.. nonce: hjyfJj
.. section: Library

Removed ``__slots__`` from :class:`typing.ParamSpec` and
:class:`typing.TypeVar`. They served no purpose. Patch by Arie Bovenberg.

..

.. 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: 46269
.. date: 2022-01-05-18-16-13
.. nonce: K16Z1S
.. section: Library

Remove special-casing of ``__new__`` in :meth:`enum.Enum.__dir__`.

..

.. bpo: 46266
.. date: 2022-01-05-12-48-18
.. nonce: ACQCgX
.. section: Library

Improve day constants in :mod:`calendar`.

Now all constants (`MONDAY` ... `SUNDAY`) are documented, tested, and added
to ``__all__``.

..

.. bpo: 46257
.. date: 2022-01-04-11-04-20
.. nonce: _o2ADe
.. section: Library

Optimized the mean, variance, and stdev functions in the statistics module.
If the input is an iterator, it is consumed in a single pass rather than
eating memory by conversion to a list.  The single pass algorithm is about
twice as fast as the previous two pass code.

..

.. bpo: 41011
.. date: 2022-01-03-21-03-50
.. nonce: uULmGi
.. section: Library

Added two new variables to *pyvenv.cfg* which is generated by :mod:`venv`
module: *executable* for the executable and *command* for the command line
used to create the environment.

..

.. 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: 46238
.. date: 2022-01-03-12-19-10
.. nonce: lANhCi
.. section: Library

Reuse ``_winapi`` constants in ``asyncio.windows_events``.

..

.. bpo: 46222
.. date: 2022-01-01-17-34-32
.. nonce: s2fzZU
.. section: Library

Adding ``SF_NOCACHE`` sendfile constant for FreeBSD for the posixmodule.

..

.. bpo: 37295
.. date: 2021-12-27-15-52-28
.. nonce: s3LPo0
.. section: Library

Add fast path for ``0 <= k <= n <= 67`` for :func:`math.comb`.

..

.. bpo: 46176
.. date: 2021-12-25-11-11-21
.. nonce: EOY9wd
.. section: Library

Adding the ``MAP_STACK`` constant for the mmap module.

..

.. bpo: 43424
.. date: 2021-12-23-14-36-58
.. nonce: d9x2JZ
.. section: Library

Deprecate :attr:`webbrowser.MacOSXOSAScript._name` and use ``name`` instead.

..

.. bpo: 45321
.. date: 2021-12-19-00-00-48
.. nonce: OyuhaY
.. section: Library

Added missing error codes to module ``xml.parsers.expat.errors``.

..

.. bpo: 46125
.. date: 2021-12-18-18-29-07
.. nonce: LLmcox
.. section: Library

Refactor tests to test traversable API directly. Includes changes from
importlib 5.4.0.

..

.. bpo: 46118
.. date: 2021-12-17-16-27-44
.. nonce: euAy0E
.. section: Library

Moved importlib.resources and its related functionality to a package.

..

.. bpo: 37578
.. date: 2021-12-17-13-22-37
.. nonce: _tluuR
.. section: Library

Add *include_hidden* parameter to :func:`~glob.glob` and :func:`~glob.iglob`
to match hidden files and directories when using special characters like
``*``, ``**``, ``?`` and ``[]``.

..

.. 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: 44893
.. date: 2021-12-16-13-54-55
.. nonce: I7aLiW
.. section: Library

EntryPoint objects are no longer tuples. Recommended means to access is by
attribute ('.name', '.group') or accessor ('.load()'). Access by index is
deprecated and will raise deprecation warning.

..

.. bpo: 22815
.. date: 2021-12-16-12-54-21
.. nonce: 0NRH8s
.. section: Library

Print unexpected successes together with failures and errors in summary in
:class:`unittest.TextTestResult`.

..

.. bpo: 22047
.. date: 2021-12-15-19-24-54
.. nonce: gBV4vT
.. section: Library

Calling :meth:`add_argument_group` on an argument group is deprecated.
Calling :meth:`add_argument_group` or :meth:`add_mutually_exclusive_group`
on a mutually exclusive group is deprecated.

These features were never supported and do not always work correctly. The
functions exist on the API by accident through inheritance and will be
removed in the future.

..

.. 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: 45615
.. date: 2021-12-13-15-51-16
.. nonce: hVx83Q
.. section: Library

Functions in the :mod:`traceback` module raise :exc:`TypeError` rather than
:exc:`AttributeError` when an exception argument is not of type
:exc:`BaseException`.

..

.. bpo: 16594
.. date: 2021-12-12-13-41-47
.. nonce: yfC7L4
.. section: Library

Add allow allow_reuse_port flag in socketserver.

..

.. 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: 46014
.. date: 2021-12-10-03-13-57
.. nonce: 3xYdST
.. section: Library

Add ability to use ``typing.Union`` and ``types.UnionType`` as dispatch
argument to ``functools.singledispatch``. Patch provided by Yurii Karabas.

..

.. bpo: 27062
.. date: 2021-12-09-11-50-32
.. nonce: R5vii6
.. section: Library

Add :attr:`__all__` to :mod:`inspect`, patch by Kumar Aditya.

..

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

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

..

.. bpo: 46016
.. date: 2021-12-08-19-15-03
.. nonce: s9PuyF
.. section: Library

Adding :attr:`F_DUP2FD` and :attr:`F_DUP2FD_CLOEXEC` constants from FreeBSD
into the fcntl module.

..

.. bpo: 45755
.. date: 2021-12-07-21-55-22
.. nonce: bRqKGa
.. section: Library

:mod:`typing` generic aliases now reveal the class attributes of the
original generic class when passed to ``dir()``. This was the behavior up to
Python 3.6, but was changed in 3.7-3.9.

..

.. bpo: 45874
.. date: 2021-12-02-11-55-45
.. nonce: dtJIsN
.. section: Library

The empty query string, consisting of no query arguments, is now handled
correctly in ``urllib.parse.parse_qsl``. This caused problems before when
strict parsing was enabled.

..

.. bpo: 44674
.. date: 2021-11-29-19-37-20
.. nonce: NijWLt
.. section: Library

Change how dataclasses disallows mutable default values.  It used to use a
list of known types (list, dict, set).  Now it disallows unhashable objects
to be defaults.  It's using unhashability as a proxy for mutability.  Patch
by Eric V. Smith, idea by Raymond Hettinger.

..

.. bpo: 23882
.. date: 2021-11-24-19-09-14
.. nonce: _tctCv
.. section: Library

Remove namespace package (PEP 420) support from unittest discovery. It was
introduced in Python 3.4 but has been broken since Python 3.7.

..

.. bpo: 25066
.. date: 2021-11-24-12-25-42
.. nonce: YIcIkn
.. section: Library

Added a :meth:`__repr__` method to  :class:`multiprocessing.Event` objects,
patch by Kumar Aditya.

..

.. bpo: 45643
.. date: 2021-10-28-11-40-59
.. nonce: jeiPiX
.. section: Library

Added :data:`signal.SIGSTKFLT` on platforms where this signal is defined.

..

.. bpo: 44092
.. date: 2021-05-19-12-35-49
.. nonce: hiSlI5
.. section: Library

Fetch across rollback no longer raises :exc:`~sqlite3.InterfaceError`.
Instead we leave it to the SQLite library to handle these cases. Patch by
Erlend E. Aasland.

..

.. bpo: 42413
.. date: 2020-11-26-10-23-46
.. nonce: HFikOl
.. section: Library

Replace ``concurrent.futures.TimeoutError`` and ``asyncio.TimeoutError``
with builtin :exc:`TimeoutError`, keep these names as deprecated aliases.

..

.. bpo: 46196
.. date: 2021-12-30-19-12-24
.. nonce: UvQ8Sq
.. section: Documentation

Document method :meth:`cmd.Cmd.columnize`.

..

.. bpo: 46120
.. date: 2021-12-21-12-45-57
.. nonce: PE0DmJ
.. section: Documentation

State that ``|`` is preferred for readability over ``Union`` in the
:mod:`typing` docs.

..

.. bpo: 46109
.. date: 2021-12-16-21-13-55
.. nonce: 0-RNzu
.. section: Documentation

Extracted ``importlib.resources`` and ``importlib.resources.abc``
documentation into separate files.

..

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

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

..

.. bpo: 46296
.. date: 2022-01-08-00-00-38
.. nonce: vqxgTm
.. section: Tests

Add a test case for :mod:`enum` with ``_use_args_ == True`` and
``_member_type_ == object``.

..

.. 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: 46262
.. date: 2022-01-05-01-38-45
.. nonce: MhiLWP
.. section: Tests

Cover ``ValueError`` path in tests for :meth:`enum.Flag._missing_`.

..

.. 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: 44133
.. date: 2022-01-12-13-42-16
.. nonce: NgyNAh
.. section: Build

When Python is configured with :option:`--without-static-libpython`, the
Python static library (libpython.a) is no longer built. Patch by Victor
Stinner.

..

.. bpo: 44133
.. date: 2022-01-12-13-34-52
.. nonce: HYCNXb
.. section: Build

When Python is built without :option:`--enable-shared`, the ``python``
program is now linked to object files, rather than being linked to the
Python static library (libpython.a), to make sure that all symbols are
exported. Previously, the linker omitted some symbols like the
:c:func:`Py_FrozenMain` function. Patch by Victor Stinner.

..

.. bpo: 40280
.. date: 2022-01-12-10-22-23
.. nonce: 5maBz8
.. section: Build

The ``configure`` script has a new option ``--with-emscripten-target`` to
select browser or node as Emscripten build target.

..

.. bpo: 46315
.. date: 2022-01-09-15-48-49
.. nonce: NdCRLu
.. section: Build

Added and fixed ``#ifdef HAVE_FEATURE`` checks for functionality that is not
available on WASI platform.

..

.. bpo: 45723
.. date: 2022-01-07-08-33-45
.. nonce: uq2nBU
.. section: Build

Fixed a regression in ``configure`` check for :func:`select.epoll`.

..

.. 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: 46088
.. date: 2021-12-16-14-18-07
.. nonce: 8UUuAd
.. section: Build

Automatically detect or install bootstrap Python runtime when building from
Visual Studio.

..

.. bpo: 46072
.. date: 2021-12-15-10-37-44
.. nonce: GgeAU3
.. section: Build

Add a --with-pystats configure option to turn on internal statistics
gathering.

..

.. bpo: 40280
.. date: 2021-12-13-21-03-52
.. nonce: b7NG4Y
.. section: Build

A new directory ``Tools/wasm`` contains WebAssembly-related helpers like
``config.site`` override for wasm32-emscripten, wasm assets generator to
bundle the stdlib, and a README.

..

.. bpo: 46023
.. date: 2021-12-09-10-25-11
.. nonce: PLpNB6
.. section: Build

:program:`makesetup` no longer builds extensions that have been marked as
*disabled*. This allows users to disable modules in ``Modules/Setup.local``.

..

.. bpo: 45949
.. date: 2021-12-02-23-21-18
.. nonce: OTSo9X
.. section: Build

Use pure Python ``freeze_module`` for all but importlib bootstrap files.
``--with-freeze-module`` :program:`configure` option is no longer needed for
cross builds.

..

.. bpo: 46217
.. date: 2022-01-07-22-55-11
.. nonce: tgJEsB
.. section: Windows

Removed parameter that is unsupported on Windows 8.1 and early Windows 10
and may have caused build or runtime failures.

..

.. 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: 46236
.. date: 2022-01-05-10-16-16
.. nonce: pcmVQw
.. section: C API

Fix a bug in :c:func:`PyFunction_GetAnnotations` that caused it to return a
``tuple`` instead of a ``dict``.

..

.. bpo: 46140
.. date: 2021-12-21-22-56-36
.. nonce: dvXkYK
.. section: C API

:c:func:`PyBuffer_GetPointer`, :c:func:`PyBuffer_FromContiguous`,
:c:func:`PyBuffer_ToContiguous` and :c:func:`PyMemoryView_FromBuffer` now
take buffer info by ``const Py_buffer *`` instead of ``Py_buffer *``, as
they do not need mutability. :c:func:`PyBuffer_FromContiguous` also now
takes the source buffer as ``const void *``, and similarly
:c:func:`PyBuffer_GetPointer` takes the strides as ``const Py_ssize_t *``.

..

.. bpo: 45855
.. date: 2021-12-12-10-09-02
.. nonce: MVsTDj
.. section: C API

Document that the *no_block* argument to :c:func:`PyCapsule_Import` is a
no-op now.

..

.. bpo: 45855
.. date: 2021-12-11-08-41-36
.. nonce: Lq2_gR
.. section: C API

Replaced deprecated usage of :c:func:`PyImport_ImportModuleNoBlock` with
:c:func:`PyImport_ImportModule` in stdlib modules. Patch by Kumar Aditya.

..

.. bpo: 46007
.. date: 2021-12-08-12-41-51
.. nonce: sMgDLz
.. section: C API

The :c:func:`PyUnicode_CHECK_INTERNED` macro has been excluded from the
limited C API. It was never usable there, because it used internal
structures which are not available in the limited C API. Patch by Victor
Stinner.