.. bpo: 42576
.. date: 2020-12-05-22-34-47
.. nonce: lEeEl7
.. release date: 2020-12-07
.. section: Core and Builtins

``types.GenericAlias`` will now raise a ``TypeError`` when attempting to
initialize with a keyword argument.  Previously, this would cause the
interpreter to crash if the interpreter was compiled with debug symbols.
This does not affect interpreters compiled for release.  Patch by Ken Jin.

..

.. bpo: 5054
.. date: 2020-12-04-03-51-12
.. nonce: 53StYZ
.. section: Library

CGIHTTPRequestHandler.run_cgi() HTTP_ACCEPT improperly parsed. Replace the
special purpose getallmatchingheaders with generic get_all method and add
relevant tests.

Original Patch by Martin Panter. Modified by Senthil Kumaran.

..

.. bpo: 17735
.. date: 2020-12-03-22-22-24
.. nonce: Qsaaue
.. section: Library

:func:`inspect.findsource` now raises :exc:`OSError` instead of
:exc:`IndexError` when :attr:`co_lineno` of a code object is greater than
the file length. This can happen, for example, when a file is edited after
it was imported.  PR by Irit Katriel.

..

.. bpo: 42116
.. date: 2020-12-03-15-42-32
.. nonce: yIwroP
.. section: Library

Fix handling of trailing comments by :func:`inspect.getsource`.

..

.. bpo: 42487
.. date: 2020-11-28-04-31-20
.. nonce: iqtC4L
.. section: Library

ChainMap.__iter__ no longer calls __getitem__ on underlying maps

..

.. bpo: 42482
.. date: 2020-11-27-16-46-58
.. nonce: EJC3sd
.. section: Library

:class:`~traceback.TracebackException` no longer holds a reference to the
exception's traceback object. Consequently, instances of TracebackException
for equivalent but non-equal exceptions now compare as equal.

..

.. bpo: 42406
.. date: 2020-11-19-10-44-41
.. nonce: r9rNCj
.. section: Library

We fixed an issue in `pickle.whichmodule` in which importing
`multiprocessing` could change the how pickle identifies which module an
object belongs to, potentially breaking the unpickling of those objects.

..

.. bpo: 34215
.. date: 2020-08-19-20-17-51
.. nonce: _Cv8c-
.. section: Library

Clarify the error message for :exc:`asyncio.IncompleteReadError` when
``expected`` is ``None``.

..

.. bpo: 12800
.. date: 2020-07-09-11-32-28
.. nonce: fNgWwx
.. section: Library

Extracting a symlink from a tarball should succeed and overwrite the symlink
if it already exists. The fix is to remove the existing file or symlink
before extraction. Based on patch by Chris AtLee, Jeffrey Kintscher, and
Senthil Kumaran.

..

.. bpo: 41473
.. date: 2020-12-04-11-47-09
.. nonce: W_updK
.. section: Tests

Reenable test_gdb on gdb 9.2 and newer:
https://bugzilla.redhat.com/show_bug.cgi?id=1866884 bug is fixed in gdb
10.1.

..

.. bpo: 42553
.. date: 2020-12-03-13-32-44
.. nonce: 2TRE2N
.. section: Tests

Fix ``test_asyncio.test_call_later()`` race condition: don't measure asyncio
performance in the ``call_later()`` unit test. The test failed randomly on
the CI.

..

.. bpo: 41116
.. date: 2020-12-04-23-09-11
.. nonce: mSbXyV
.. section: macOS

If no explicit macOS SDK was specified, setup.py should check for Tcl and TK
frameworks in /Library/Frameworks; the previous commit inadvertently broke
that test.

..

.. bpo: 42504
.. date: 2020-12-02-15-48-40
.. nonce: RQmMOR
.. section: macOS

Fix build on macOS Big Sur when MACOSX_DEPLOYMENT_TARGET=11

..

.. bpo: 42508
.. date: 2020-11-30-19-46-05
.. nonce: fE7w4M
.. section: IDLE

Keep IDLE running on macOS.  Remove obsolete workaround that prevented
running files with shortcuts when using new universal2 installers built on
macOS 11.