cpython/Misc/NEWS.d/3.12.0b2.rst

.. date: 2023-06-01-03-24-58
.. gh-issue: 103142
.. nonce: GLWDMX
.. release date: 2023-06-06
.. section: Security

The version of OpenSSL used in our binary builds has been upgraded to 1.1.1u
to address several CVEs.

..

.. date: 2023-05-24-09-29-08
.. gh-issue: 99108
.. nonce: hwS2cr
.. section: Security

Refresh our new HACL* built-in :mod:`hashlib` code from upstream. Built-in
SHA2 should be faster and an issue with SHA3 on 32-bit platforms is fixed.

..

.. date: 2023-06-06-11-37-53
.. gh-issue: 105259
.. nonce: E2BGKL
.. section: Core and Builtins

Don't include newline character for trailing ``NEWLINE`` tokens emitted in
the :mod:`tokenize` module. Patch by Pablo Galindo

..

.. date: 2023-06-05-17-35-50
.. gh-issue: 105324
.. nonce: BqhiJJ
.. section: Core and Builtins

Fix the main function of the :mod:`tokenize` module when reading from
``sys.stdin``. Patch by Pablo Galindo

..

.. date: 2023-06-02-17-39-19
.. gh-issue: 98963
.. nonce: J4wJgk
.. section: Core and Builtins

Restore the ability for a subclass of :class:`property` to define
``__slots__`` or otherwise be dict-less by ignoring failures to set a
docstring on such a class.  This behavior had regressed in 3.12beta1.  An
:exc:`AttributeError` where there had not previously been one was disruptive
to existing code.

..

.. date: 2023-06-02-11-37-12
.. gh-issue: 105194
.. nonce: 4eu56B
.. section: Core and Builtins

Do not escape with backslashes f-string format specifiers. Patch by Pablo
Galindo

..

.. date: 2023-06-01-11-37-03
.. gh-issue: 105162
.. nonce: r8VCXk
.. section: Core and Builtins

Fixed bug in generator.close()/throw() where an inner iterator would be
ignored when the outer iterator was instrumented.

..

.. date: 2023-05-31-19-35-22
.. gh-issue: 105164
.. nonce: 6Wajph
.. section: Core and Builtins

Ensure annotations are set up correctly if the only annotation in a block is
within a :keyword:`match` block. Patch by Jelle Zijlstra.

..

.. date: 2023-05-31-08-10-59
.. gh-issue: 104799
.. nonce: 8kDWti
.. section: Core and Builtins

Attributes of :mod:`ast` nodes that are lists now default to the empty list
if omitted. This means that some code that previously raised
:exc:`TypeError` when the AST node was used will now proceed with the empty
list instead. Patch by Jelle Zijlstra.

..

.. date: 2023-05-30-08-09-43
.. gh-issue: 105035
.. nonce: OWUlHy
.. section: Core and Builtins

Fix :func:`super` calls on types with custom :attr:`tp_getattro`
implementation (e.g. meta-types.)

..

.. date: 2023-05-27-21-50-48
.. gh-issue: 105017
.. nonce: 4sDyDV
.. section: Core and Builtins

Show CRLF lines in the tokenize string attribute in both NL and NEWLINE
tokens. Patch by Marta Gómez.

..

.. date: 2023-05-27-16-57-11
.. gh-issue: 105013
.. nonce: IsDgDY
.. section: Core and Builtins

Fix handling of multiline parenthesized lambdas in
:func:`inspect.getsource`. Patch by Pablo Galindo

..

.. date: 2023-05-27-16-23-16
.. gh-issue: 105017
.. nonce: KQrsC0
.. section: Core and Builtins

Do not include an additional final ``NL`` token when parsing files having
CRLF lines. Patch by Marta Gómez.

..

.. date: 2023-05-26-15-16-11
.. gh-issue: 104976
.. nonce: 6dLitD
.. section: Core and Builtins

Ensure that trailing ``DEDENT`` :class:`tokenize.TokenInfo` objects emitted
by the :mod:`tokenize` module are reported as in Python 3.11. Patch by Pablo
Galindo

..

.. date: 2023-05-26-14-09-47
.. gh-issue: 104972
.. nonce: El2UjE
.. section: Core and Builtins

Ensure that the ``line`` attribute in :class:`tokenize.TokenInfo` objects in
the :mod:`tokenize` module are always correct. Patch by Pablo Galindo

..

.. date: 2023-05-25-21-40-39
.. gh-issue: 104955
.. nonce: LZx7jf
.. section: Core and Builtins

Fix signature for the new :meth:`~object.__release_buffer__` slot. Patch by
Jelle Zijlstra.

..

.. date: 2023-05-24-12-10-54
.. gh-issue: 104690
.. nonce: HX3Jou
.. section: Core and Builtins

Starting new threads and process creation through :func:`os.fork` during
interpreter shutdown (such as from :mod:`atexit` handlers) is no longer
supported.  It can lead to race condition between the main Python runtime
thread freeing thread states while internal :mod:`threading` routines are
trying to allocate and use the state of just created threads. Or forked
children trying to use the mid-shutdown runtime and thread state in the
child process.

..

.. date: 2023-05-24-10-19-35
.. gh-issue: 104879
.. nonce: v-29NL
.. section: Core and Builtins

Fix crash when accessing the ``__module__`` attribute of type aliases
defined outside a module. Patch by Jelle Zijlstra.

..

.. date: 2023-05-24-09-59-56
.. gh-issue: 104825
.. nonce: mQesie
.. section: Core and Builtins

Tokens emitted by the :mod:`tokenize` module do not include an implicit
``\n`` character in the ``line`` attribute anymore. Patch by Pablo Galindo

..

.. date: 2023-06-04-12-16-47
.. gh-issue: 105280
.. nonce: srRbCe
.. section: Library

Fix bug where ``isinstance([], collections.abc.Mapping)`` could evaluate to
``True`` if garbage collection happened at the wrong time. The bug was
caused by changes to the implementation of :class:`typing.Protocol` in
Python 3.12.

..

.. date: 2023-06-02-14-57-11
.. gh-issue: 105239
.. nonce: SAmuuj
.. section: Library

Fix longstanding bug where ``issubclass(object, typing.Protocol)`` would
evaluate to ``True`` in some edge cases. Patch by Alex Waygood.

..

.. date: 2023-06-02-02-38-26
.. gh-issue: 105080
.. nonce: 2imGMg
.. section: Library

Fixed inconsistent signature on derived classes for
:func:`inspect.signature`

..

.. date: 2023-05-31-16-58-42
.. gh-issue: 105144
.. nonce: Oqfn0V
.. section: Library

Fix a recent regression in the :mod:`typing` module. The regression meant
that doing ``class Foo(X, typing.Protocol)``, where ``X`` was a class that
had :class:`abc.ABCMeta` as its metaclass, would then cause subsequent
``isinstance(1, X)`` calls to erroneously raise :exc:`TypeError`. Patch by
Alex Waygood.

..

.. date: 2023-05-30-21-27-41
.. gh-issue: 105113
.. nonce: bDUPl_
.. section: Library

Improve performance of :meth:`pathlib.PurePath.match` by compiling an
:class:`re.Pattern` object for the entire pattern.

..

.. date: 2023-05-26-01-31-30
.. gh-issue: 101588
.. nonce: RaqxFy
.. section: Library

Deprecate undocumented copy/deepcopy/pickle support for itertools.

..

.. date: 2023-05-25-23-34-54
.. gh-issue: 103631
.. nonce: x5Urye
.. section: Library

Fix ``pathlib.PurePosixPath(pathlib.PureWindowsPath(...))`` not converting
path separators to restore 3.11 compatible behavior.

..

.. date: 2023-05-25-22-54-20
.. gh-issue: 104947
.. nonce: hi6TUr
.. section: Library

Make comparisons between :class:`pathlib.PureWindowsPath` objects consistent
across Windows and Posix to match 3.11 behavior.

..

.. date: 2023-05-25-08-50-47
.. gh-issue: 104935
.. nonce: -rm1BR
.. section: Library

Fix bugs with the interaction between :func:`typing.runtime_checkable` and
:class:`typing.Generic` that were introduced by the :pep:`695`
implementation. Patch by Jelle Zijlstra.

..

.. date: 2023-05-24-09-34-23
.. gh-issue: 104874
.. nonce: oqyJSy
.. section: Library

Document the ``__name__`` and ``__supertype__`` attributes of
:class:`typing.NewType`. Patch by Jelle Zijlstra.

..

.. date: 2023-05-23-18-31-49
.. gh-issue: 104799
.. nonce: MJYOw6
.. section: Library

Adjust the location of the (see :pep:`695`) ``type_params`` field on
:class:`ast.ClassDef`, :class:`ast.AsyncFunctionDef`, and
:class:`ast.FunctionDef` to better preserve backward compatibility. Patch by
Jelle Zijlstra

..

.. date: 2023-05-23-17-43-52
.. gh-issue: 104797
.. nonce: NR7KzF
.. section: Library

Allow :class:`typing.Protocol` classes to inherit from
:class:`collections.abc.Buffer`. Patch by Jelle Zijlstra.

..

.. date: 2023-05-22-18-39-53
.. gh-issue: 104372
.. nonce: 7tDRaK
.. section: Library

On Linux where :mod:`subprocess` can use the ``vfork()`` syscall for faster
spawning, prevent the parent process from blocking other threads by dropping
the GIL while it waits for the vfork'ed child process ``exec()`` outcome.
This prevents spawning a binary from a slow filesystem from blocking the
rest of the application.

..

.. date: 2023-05-19-19-46-22
.. gh-issue: 99108
.. nonce: wqCg0t
.. section: Library

We now release the GIL around built-in :mod:`hashlib` computations of
reasonable size for the SHA families and MD5 hash functions, matching what
our OpenSSL backed hash computations already does.

..

.. date: 2023-05-11-23-03-00
.. gh-issue: 104399
.. nonce: MMatTP
.. section: Library

Prepare the ``_tkinter`` module for building with Tcl 9.0 and future
libtommath by replacing usage of deprecated functions
:c:func:`mp_to_unsigned_bin_n` and :c:func:`mp_unsigned_bin_size` when
necessary.

..

.. date: 2023-02-18-22-55-48
.. gh-issue: 102024
.. nonce: RUmg_D
.. section: Library

Reduce calls of ``_idle_semaphore.release()`` in
:func:`concurrent.futures.thread._worker`.

..

.. date: 2023-05-28-21-01-00
.. gh-issue: 89455
.. nonce: qAKRrA
.. section: Documentation

Add missing documentation for the ``max_group_depth`` and
``max_group_width`` parameters and the ``exceptions`` attribute of the
:class:`traceback.TracebackException` class.

..

.. date: 2023-05-28-19-08-42
.. gh-issue: 89412
.. nonce: j4cg7K
.. section: Documentation

Add missing documentation for the ``end_lineno`` and ``end_offset``
attributes of the :class:`traceback.TracebackException` class.

..

.. date: 2023-05-25-22-34-31
.. gh-issue: 104943
.. nonce: J2v1Pc
.. section: Documentation

Remove mentions of old Python versions in :class:`typing.NamedTuple`.

..

.. date: 2023-06-06-09-08-10
.. gh-issue: 90005
.. nonce: 8mmeJQ
.. section: Build

Fix a regression in :file:`configure` where we could end up unintentionally
linking with ``libbsd``.

..

.. date: 2023-05-26-15-44-20
.. gh-issue: 89886
.. nonce: _iSW-p
.. section: Build

Autoconf 2.71 and aclocal 1.16.4 is now required to regenerate
:file:`!configure`.

..

.. date: 2023-05-31-16-14-31
.. gh-issue: 105146
.. nonce: gNjqq8
.. section: Windows

Updated the links at the end of the installer to point to Discourse rather
than the mailing lists.

..

.. date: 2023-05-29-17-09-31
.. gh-issue: 103646
.. nonce: U8oGQx
.. section: Windows

When installed from the Microsoft Store, ``pip`` no longer defaults to
per-user installs. However, as the install directory is unwritable, it
should automatically decide to do a per-user install anyway. This should
resolve issues when ``pip`` is passed an option that conflicts with
``--user``.

..

.. date: 2023-05-29-11-38-53
.. gh-issue: 88745
.. nonce: cldf9G
.. section: Windows

Improve performance of :func:`shutil.copy2` by using the operating system's
``CopyFile2`` function. This may result in subtle changes to metadata copied
along with some files, bringing them in line with normal OS behavior.

..

.. date: 2023-05-24-21-00-57
.. gh-issue: 104820
.. nonce: ibyrpp
.. section: Windows

Fixes :func:`~os.stat` and related functions on file systems that do not
support file ID requests. This includes FAT32 and exFAT.

..

.. date: 2023-05-23-19-26-28
.. gh-issue: 104803
.. nonce: gqxYml
.. section: Windows

Add :func:`os.path.isdevdrive` to detect whether a path is on a Windows Dev
Drive. Returns ``False`` on platforms that do not support Dev Drive, and is
absent on non-Windows platforms.

..

.. date: 2023-05-30-23-30-46
.. gh-issue: 103142
.. nonce: 55lMXQ
.. section: macOS

Update macOS installer to use OpenSSL 1.1.1u.

..

.. date: 2023-05-23-17-19-49
.. gh-issue: 104719
.. nonce: rvYXH-
.. section: IDLE

Remove IDLE's modification of tokenize.tabsize and test other uses of
tokenize data and methods.

..

.. date: 2023-05-30-17-45-32
.. gh-issue: 105115
.. nonce: iRho1K
.. section: C API

``PyTypeObject.tp_bases`` (and ``tp_mro``) for builtin static types are now
shared by all interpreters, whereas in 3.12-beta1 they were stored on
``PyInterpreterState``.  Also note that now the tuples are immortal objects.

..

.. date: 2023-05-30-10-15-13
.. gh-issue: 105071
.. nonce: dPtp7c
.. section: C API

Add ``PyUnstable_Exc_PrepReraiseStar`` to the unstable C api to expose the
implementation of :keyword:`except* <except_star>`.

..

.. date: 2023-05-19-10-22-34
.. gh-issue: 104668
.. nonce: MLX1g9
.. section: C API

Don't call :c:var:`PyOS_InputHook` or :c:var:`PyOS_ReadlineFunctionPointer`
in subinterpreters, since it's generally difficult to avoid using global
state in their registered callbacks. This also avoids situations where
extensions may find themselves running in a subinterpreter they don't
support (or haven't yet been loaded in).