Update cython to 3.2.4 by pyup-bot · Pull Request #2420 · MBARIMike/stoqs

pyup-bot · 2026-01-04T15:54:07Z

This PR updates Cython from 3.0.10 to 3.2.4.

Changelog

3.2.4

==================

Features added
--------------

* In preparation of Cython 3.3, a new decorator ``collection_type(tname)`` can be used
to advertise an extension type as being a ``&#x27;sequence&#x27;`` or ``&#x27;mapping&#x27;``.  This currently
only has the effect of setting the ``Py_TPFLAGS_SEQUENCE`` flag on the type or not, but
is provided for convenience to allow using the new decorator already in Cython 3.2 code.

* Several C++ exception declarations were added to ``libcpp.exceptions``.
(Github issue :issue:`7389`)

Bugs fixed
----------

* Pseudo-literal default values of function arguments like ``arg=str()`` could generate
invalid C code when internally converted into a real literal.
(Github issue :issue:`6192`)

* The pickle serialisation of extension types using the ``auto_pickle`` feature was
larger than necessary since 3.2.0 for types without Python object attributes.
It is now back to the state before 3.2.0 again.
(Github issue :issue:`7443`)

* Constants are now only made immortal on freethreading Python if they are not shared.
(Github issue :issue:`7439`)

* ``PyDict_SetDefaultRef()`` is now used when available to avoid temporary borrowed references.
(Github issue :issue:`7347`)

* Includes all fixes as of Cython 3.1.8.

3.2.3

==================

Features added
--------------

* The C-API declarations were updated to include the new ``PyList_*()`` functions.
(Github issue :issue:`7291`)

* The ``Py_mod_gil`` module setting can now be changed with a C macro, overriding
the ``freethreading_compatible`` directive setting.
(Github issue :issue:`7404`)

Bugs fixed
----------

* t-strings lost the last element when compiled for the Limited API.
(Github issue :issue:`7381`)

* The ``array.data`` property of the ``cpython.array`` declarations generated a
useless exception check that degraded its use in ``nogil`` code.
(Github issue :issue:`7408`)

* Parallel builds with the ``cythonize`` command could request more processes
than allowed by the platform, thus failing the build.
(Github issue :issue:`7384`)

* A minor thread sanitizer issue was resolved.
(Github issue :issue:`7383`)

3.2.2

==================

Features added
--------------

* The C-API declarations were updated to include the new ``PyDict_*Ref()`` functions.
(Github issue :issue:`7291`)

Bugs fixed
----------

* Iteration over literal sequences and strings in generators generated invalid C code since 3.2.0.
This was a regression due to the C array iteration optimisation in :issue:`6926`, which is now
disabled inside of generators.
(Github issue :issue:`7342`)

* Calling special methods of known exception types failed with an ``AttributeError``.
(Github issue :issue:`7342`)

* Calling the unbound ``__mul__`` special method of builtin collections with subtypes failed.
(Github issue :issue:`7340`)

* C string literals could generate invalid &quot;const to non-const&quot; casts in the C code.
(Github issue :issue:`7346`)

* ``yield`` is no longer allowed inside of a ``cython.critical_section``,
but *is* now allowed while holding a ``cython.pymutex``.
(Github issue :issue:`7317`)

* Under lock congestion, acquiring the GIL could crash in Python 3.11, part 2.
This bug was introduced in Cython 3.2.0.
(Github issue :issue:`7312`)

* The new ``py_safe_*`` functions in ``libc.threads`` triggered C compiler warnings.
(Github issue :issue:`7356`)

3.2.1

==================

Features added
--------------

* Cython now leaves markers about its utility code dependencies in the generated C code
to help debugging &quot;unused function&quot; C compiler warnings.
(Github issue :issue:`7294`)

Bugs fixed
----------

* Relative imports could fail if the shared utility module is used.
This bug was introduced in Cython 3.2.0.
(Github issue :issue:`7290`)

* Under lock congestion, acquiring the GIL could crash in Python 3.11.
This bug was introduced in Cython 3.2.0.
(Github issue :issue:`7312`)

* Using the shared utility module left an unused C function in user modules with memoryviews.
To make debugging this kind of issue easier, Cython now leaves &quot;used by …&quot; markers in the
generated C files that indicate why a specific piece of utility code was included.
This bug was introduced in Cython 3.2.0.
(Github issue :issue:`7293`)

* Code using the pre-import scope failed with an undefined name.
This bug was introduced in Cython 3.2.0.
(Github issue :issue:`7304`)

* Includes all fixes as of Cython 3.1.7.

3.2.0

==================

(Complete changelog for the 3.2.0 release, including pre-releases.)

Features added
--------------

* Builtin exception types are now inferred.
(Github issue :issue:`6908`)

* The list of known, inferred and optimised Python builtins was updated.
`range` is now considered a type. `ascii`, `bin`, `format`, `hex`, `oct` were added as functions.
(Github issue :issue:`6931`)

* The f-string syntax was extended according to PEP-701.
(Github issue :issue:`5452`)

* t-strings are implemented according to PEP-750.  The implementation backports the template classes
but prefers existing backports if installed separately.
(Github issue :issue:`6811`)

* Unknown return type annotations with `-&gt;` are no longer rejected but produce warnings.
This allows better integration with Python type hints that are not always usable for Cython.
``-&gt; None``  is also allowed now.
Patch by jpe.  (Github issue :issue:`6946`)

* The runtime Python dispatch for fused functions is substantially faster.
(Github issues :issue:`1385`, :issue:`6996`)

* Freelists (via cdef class decorator and for internally used types such as ``async``)
are now also used in the Limited API and with extension type specs enabled.
(Github issue :issue:`7151`)

* Module imports now quickly check for an already imported module to speed up reimports.
Patch by Lysandros Nikolaou.  (Github issue :issue:`7035`)

* Type checks on PEP-604 union types (`int | None`) are optimised into separate checks.
(Github issue :issue:`6935`)

* Assignments to the PEP-604 union type `float | None` allow any suitable Python number as input
and convert it to a Python `float` automatically.
(Github issue :issue:`5750`)

* Item type inference was improved for looping over literals.
(Github issue :issue:`6912`)

* Looping over literal sequences and strings now uses efficient C array looping if possible.
(Github issue :issue:`6926`)

* Releasing the GIL from an unknown lock state is more efficient.
(Github issue :issue:`6847`)

* ``cython.critical_section(PyMutex)`` now works, as with Python objects.
(Github issue :issue:`6847`)

* ``bool(c_int/float/ptr)`` avoid passing through Python objects.
(Github issue :issue:`7015`)

* Variables assigned inside of ``prange`` loops can now be initialised outside of the loop.
(Github issue :issue:`7178`)

* Unused exceptions in ``except`` clauses are detected in some more cases to avoid their normalisation.
(Github issue :issue:`7021`)

* Mixed operations on C integers with Python ints use less code and are more streamlined for Py3.12+.
(Github issue :issue:`7244`)

* Some object constants are now marked as ``immortal`` to speed up their reference counting
in recent CPython versions.  This can be configured with the ``CYTHON_IMMORTAL_CONSTANTS`` C macro.
(Github issue :issue:`7118`)

* Further improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`6983`, :issue:`7199`, :issue:`7220`, :issue:`7238`,
:issue:`7255`, :issue:`7265`)

* Several improvements were made in freethreaded Python code.
(Github issues :issue:`6936`, :issue:`6939`, :issue:`6949`, :issue:`6984`,
:issue:`7011`, :issue:`7066`, :issue:`7114`, :issue:`7200`)

* Several improvements were made for the Limited API.
(Github issues :issue:`6959`, :issue:`6991`)

* Several improvements were made for the GraalPython support.
Patch by Michael Šimáček.  (Github issue :issue:`7074`)

* Some GIL-safe C-API wrappers were added to the libc/libcpp declarations.
(Github issue :issue:`6829`, :issue:`6993`)

* String and number constants use less storage space in the module.
(Github issues :issue:`6971`, :issue:`6978`, :issue:`6986`)

* The managed dict/weakref support in CPython 3.12+ is used for internal types
to benefit from future CPython optimisations here.
(Github issue :issue:`6891`)

* Using ``NaN`` as exception return value is supported.
(Github issues :issue:`6900`, :issue:`6903`)

* Declarations for C++ condition variables were added.
(Github issue :issue:`6836`)

* The annotated source HTML page shows alternating +/− markers to open/close lines.
Patch by Kamil Monicz.  (Github issue :issue:`7099`)

* ``cython --embed`` gained a new option ``--embed-modules=…`` to list further extension modules
that will be statically linked into the generated extension module, to get them initialised
on application start.
(Github issue :issue:`2849`)

* The ``setup.py`` script of Cython now allows passing the desired Limited API version
like ``--cython-limited-api=3.11``.
(Github issue :issue:`7228`)

* Unicode 16.0.0 is used to parse identifiers.

Bugs fixed
----------

* Special float exception values could generate invalid C code.
(Github issues :issue:`6900`, :issue:`6903`)

* References to the Python ``bool`` type could generate invalid C code.
(Github issue :issue:`6902`)

* Using ``cython.pymutex`` in an extension type declared as ``public`` or ``api``
generated invalid C code missing the required ``PyMutex`` declarations.
(Github issues :issue:`6992`, :issue:`6995`)

* Cython&#x27;s type sharing across modules suffered from race conditions if multiple modules
tried to initialise and share their types concurrently.  This is due to an underlying
CPython issue and cannot easily be worked around completely.  In the common case that
module dicts are plain Python dict objects, however, Cython now uses a ``.setdefault()``
equivalent for thread-safe type sharing.
See https://github.com/python/cpython/issues/137422
(Github issue :issue:`7076`)

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

* Iterating over temporary memoryviews could crash Cython.
(Github issue :issue:`7005`)

* Type casts on constants as part of numeric expressions could crash Cython.
(Github issue :issue:`6779`)

* Long code bodies in ``with`` statements could crash Cython.
(Github issue :issue:`7122`)

* Vectorcalls could use needless temp assignments for ``self``.
(Github issue :issue:`6909`)

* Indexing ``bytes`` failed to optimise in some cases.
(Github issue :issue:`6997`)

* Optimised C integer formatting in f-strings failed to apply to typedef types.
(Github issue :issue:`7170`)

* In auto-pickling, trying to unpickle an object that has no ``__dict__`` from object pickle data
that includes instance dict state is now an error.
(Github issue :issue:`7222`)

* The type objects of heap types were not always correctly decrefed on deallocation.
(Github issue :issue:`7145`)

* Pure mode type aliases like ``p_int`` or ``ulong`` leaked into some C type contexts,
risking to conflict with user declarations.
(Github issues :issue:`6922`, :issue:`6339`)

* Boolean (emptyness) tests on builtin containers could fail to handle (unlikely) errors.
(Github issue :issue:`7090`)

* The return type of ``bytes.join()`` was sometimes inferred as plain ``object``.
(Github issue :issue:`6987`)

* Type inference could fail to understand ``prange()`` arguments.
(Github issue :issue:`6974`)

* ``embedsignatures`` failed if ``lambda`` was used in function default arguments.
(Github issue :issue:`6880`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* ``PyType_FromModuleAndSpec`` was incorrectly used in Limited API code before Py3.10.
(Github issue :issue:`7181`)

* Conversion code for memoryview dtypes from and to Python objects generated C warnings about
incorrect ``const`` / non-``const``  casting code.
(Github issue :issue:`7219`)

* Cython&#x27;s tools and frontend scripts now use ``python3``  instead of just ``python``
in their shebang line.
Patch by Matti Picus.  (Github issue :issue:`7053`)

* Extension arguments defined for the shared code module were ignored in ``cythonize()``.
(Github issue :issue:`7251`)

* Failures while following package attributes in ``import pkg.module as …`` were not handled.

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

* The ``setup.py`` script in the ``Demos/`` subdirectory failed to build.
(Github issue :issue:`7228`)

* The ``cygdb`` program failed to work with virtualenvs on Windows.
Patch by Merlin.  (Github issue :issue:`7268`)

* Includes all fixes as of Cython 3.1.6.

Other changes
-------------

* Some lesser used platforms (Windows ARM/i686, macOS x86_64, Linux i686, musllinux)
now use Py3.9 abi3 binary wheels instead of Python version specific wheels.
We also added an abi3 wheel for armv7l.
(Github issues :issue:`7227`, :issue:`7248`, :issue:`7250`)

* Usages of `Py_TPFLAGS_HAVE_FINALIZE` were removed.  The constant remains available as cimport from
``cpython.object`` for legacy reasons.
(Github issue :issue:`6423`)

3.2.0b3

====================

Bugs fixed
----------

* Using ``cython.pymutex`` in an extension type declared as ``public`` or ``api``
generated invalid C code missing the required ``PyMutex`` declarations.
(Github issues :issue:`6992`, :issue:`6995`)

* 3.2.0b2 generated incorrect pointer casts in the ``cimport`` importing code.
(Github issue :issue:`7268`)

* Cython&#x27;s type sharing across modules suffered from race conditions if multiple modules
tried to initialise and share their types concurrently.  This is due to an underlying
CPython issue and cannot easily be worked around completely.  In the common case that
module dicts are plain Python dict objects, however, Cython now uses a ``.setdefault()``
equivalent for thread-safe type sharing.
See https://github.com/python/cpython/issues/137422
(Github issue :issue:`7076`)

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

3.2.0b2

====================

Features added
--------------

* The code generated for importing and exporting cimports across modules uses less space.
(Github issues :issue:`7255`, :issue:`7265`)

Bugs fixed
----------

* Iteration over memoryviews could loop indefinitely in 3.2b1 when encountering a ``continue`` statement.
(Github issue :issue:`7259`)

* Extension arguments defined for the shared code module were ignored in ``cythonize()``.
(Github issue :issue:`7251`)

* Failures while following package attributes in ``import pkg.module as …`` were not handled.

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

* Includes all fixes as of Cython 3.1.6.

Other changes
-------------

* The ``musllinux`` platform is now served with an abi3 Cython wheel instead of Python specific ones.
(Github issue :issue:`7250`)

3.2.0b1

====================

Features added
--------------

* Builtin exception types are now inferred.
(Github issue :issue:`6908`)

* The list of known, inferred and optimised Python builtins was updated.
`range` is now considered a type. `ascii`, `bin`, `format`, `hex`, `oct` were added as functions.
(Github issue :issue:`6931`)

* The f-string syntax was extended according to PEP-701.
(Github issue :issue:`5452`)

* t-strings are implemented according to PEP-750.  The implementation backports the template classes
but prefers existing backports if installed separately.
(Github issue :issue:`6811`)

* Unknown return type annotations with `-&gt;` are no longer rejected but produce warnings.
This allows better integration with Python type hints that are not always usable for Cython.
``-&gt; None``  is also allowed now.
Patch by jpe.  (Github issue :issue:`6946`)

* The runtime Python dispatch for fused functions is substantially faster.
(Github issues :issue:`1385`, :issue:`6996`)

* Freelists (via cdef class decorator and for internally used types such as ``async``)
are now also used in the Limited API and with extension type specs enabled.
(Github issue :issue:`7151`)

* Module imports now quickly check for an already imported module to speed up reimports.
Patch by Lysandros Nikolaou.  (Github issue :issue:`7035`)

* Type checks on PEP-604 union types (`int | None`) are optimised into separate checks.
(Github issue :issue:`6935`)

* Assignments to the PEP-604 union type `float | None` allow any suitable Python number as input
and convert it to a Python `float` automatically.
(Github issue :issue:`5750`)

* Item type inference was improved for looping over literals.
(Github issue :issue:`6912`)

* Looping over literal sequences and strings now uses efficient C array looping if possible.
(Github issue :issue:`6926`)

* Releasing the GIL from an unknown lock state is more efficient.
(Github issue :issue:`6847`)

* ``cython.critical_section(PyMutex)`` now works, as with Python objects.
(Github issue :issue:`6847`)

* ``bool(c_int/float/ptr)`` avoid passing through Python objects.
(Github issue :issue:`7015`)

* Variables assigned inside of ``prange`` loops can now be initialised outside of the loop.
(Github issue :issue:`7178`)

* Unused exceptions in ``except`` clauses are detected in some more cases to avoid their normalisation.
(Github issue :issue:`7021`)

* Mixed operations on C integers with Python ints use less code and are more streamlined for Py3.12+.
(Github issue :issue:`7244`)

* Some object constants are now marked as ``immortal`` to speed up their reference counting
in recent CPython versions.  This can be configured with the ``CYTHON_IMMORTAL_CONSTANTS`` C macro.
(Github issue :issue:`7118`)

* Further improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`6983`, :issue:`7199`, :issue:`7220`, :issue:`7238`)

* Several improvements were made in freethreaded Python code.
(Github issues :issue:`6936`, :issue:`6939`, :issue:`6949`, :issue:`6984`,
:issue:`7011`, :issue:`7066`, :issue:`7114`, :issue:`7200`)

* Several improvements were made for the Limited API.
(Github issues :issue:`6959`, :issue:`6991`)

* Several improvements were made for the GraalPython support.
Patch by Michael Šimáček.  (Github issue :issue:`7074`)

* Some GIL-safe C-API wrappers were added to the libc/libcpp declarations.
(Github issue :issue:`6829`, :issue:`6993`)

* String and number constants use less storage space in the module.
(Github issues :issue:`6971`, :issue:`6978`, :issue:`6986`)

* The managed dict/weakref support in CPython 3.12+ is used for internal types
to benefit from future CPython optimisations here.
(Github issue :issue:`6891`)

* Using ``NaN`` as exception return value is supported.
(Github issues :issue:`6900`, :issue:`6903`)

* Declarations for C++ condition variables were added.
(Github issue :issue:`6836`)

* The annotated source HTML page shows alternating +/− markers to open/close lines.
Patch by Kamil Monicz.  (Github issue :issue:`7099`)

* ``cython --embed`` gained a new option ``--embed-modules=…`` to list further extension modules
that will be statically linked into the generated extension module, to get them initialised
on application start.
(Github issue :issue:`2849`)

* The ``setup.py`` script of Cython now allows passing the desired Limited API version
like ``--cython-limited-api=3.11``.
(Github issue :issue:`7228`)

* Unicode 16.0.0 is used to parse identifiers.
(Github issue :issue:`6836`)

Bugs fixed
----------

* Special float exception values could generate invalid C code.
(Github issues :issue:`6900`, :issue:`6903`)

* References to the Python ``bool`` type could generate invalid C code.
(Github issue :issue:`6902`)

* Unicode characters formatted from C integers with ``f&quot;{value:c}&quot;`` could result in
invalid Python string objects since Cython 3.1.0.
(Github issue :issue:`7240`)

* Vectorcalls could use needless temp assignments for ``self``.
(Github issue :issue:`6909`)

* Iterating over temporary memoryviews could crash Cython.
(Github issue :issue:`7005`)

* Type casts on constants as part of numeric expressions could crash Cython.
(Github issue :issue:`6779`)

* Long code bodies in ``with`` statements could crash Cython.
(Github issue :issue:`7122`)

* Indexing ``bytes`` failed to optimise in some cases.
(Github issue :issue:`6997`)

* Optimised C integer formatting in f-strings failed to apply to typedef types.
(Github issue :issue:`7170`)

* In auto-pickling, trying to unpickle an object that has no ``__dict__`` from object pickle data
that includes instance dict state is now an error.
(Github issue :issue:`7222`)

* The type objects of heap types were not always correctly decrefed on deallocation.
(Github issue :issue:`7145`)

* Pure mode type aliases like ``p_int`` or ``ulong`` leaked into some C type contexts,
risking to conflict with user declarations.
(Github issues :issue:`6922`, :issue:`6339`)

* Boolean (emptyness) tests on builtin containers could fail to handle (unlikely) errors.
(Github issue :issue:`7090`)

* The return type of ``bytes.join()`` was sometimes inferred as plain ``object``.
(Github issue :issue:`6987`)

* Type inference could fail to understand ``prange()`` arguments.
(Github issue :issue:`6974`)

* ``embedsignatures`` failed if ``lambda`` was used in function default arguments.
(Github issue :issue:`6880`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* ``PyType_FromModuleAndSpec`` was incorrectly used in Limited API code before Py3.10.
(Github issue :issue:`7181`)

* Conversion code for memoryview dtypes from and to Python objects generated C warnings about
incorrect ``const`` / non-``const``  casting code.
(Github issue :issue:`7219`)

* ``cythonize`` (program and function) now uses ``concurrent.futures.ProcessPoolExecutor``
instead of ``multiprocessing.Pool`` to fix a hang on build failures in parallel builds.
A possible work-around is to disable parallel builds.
Patch by Sviatoslav Sydorenko.  (Github issue :issue:`7183`)

* Cython&#x27;s tools and frontend scripts now use ``python3``  instead of just ``python``
in their shebang line.
Patch by Matti Picus.  (Github issue :issue:`7053`)

* The ``setup.py`` script in the ``Demos/`` subdirectory failed to build.
(Github issue :issue:`7228`)

* Includes all fixes as of Cython 3.1.5.

Other changes
-------------

* Some lesser used platforms (Windows ARM/i686, macOS x86_64, Linux i686) now use Py3.9 abi3 binary wheels
instead of Python version specific wheels.  We also added a abi3 wheel for armv7l.
(Github issues :issue:`7227`, :issue:`7248`)

* Usages of `Py_TPFLAGS_HAVE_FINALIZE` were removed.  The constant remains available as cimport from
``cpython.object`` for legacy reasons.
(Github issue :issue:`6423`)

3.1.8

==================

Bugs fixed
----------

* Assignment expressions used in comprehensions could look at the wrong scope,
thus using different variables and different data.
(Github issue :issue:`6547`)

* Some internal C symbols were not declared as ``static``, preventing static linking
of multiple modules.
Patch by Yury Popov.  (Github issue :issue:`7310`)

* Accidentally using ``except +`` in C mode did not raise a compile error but generated
invalid C code leading to obscure error messages.
Patch by user202729.  (Github issue :issue:`6560`)

3.1.7

==================

Bugs fixed
----------

* Unicode characters formatted from C integers with padding, as in ``f&quot;{value:XXc}&quot;``,
could result in invalid Python string objects since Cython 3.1.0.
Also, lone surrogates failed to format in this way.
(Github issue :issue:`7298`)

* Assigning nested structs from a list of structs (item by item) could crash Cython.
(Github issue :issue:`7308`)

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

3.1.6

==================

Bugs fixed
----------

* Unicode characters formatted from C integers with ``f&quot;{value:c}&quot;`` could result in
invalid Python string objects since Cython 3.1.0.
(Github issue :issue:`7240`)

* ``cythonize`` (program and function) now uses ``concurrent.futures.ProcessPoolExecutor``
instead of ``multiprocessing.Pool`` to fix a hang on build failures in parallel builds.
A possible work-around is to disable parallel builds.
Patch by Sviatoslav Sydorenko.  (Github issue :issue:`7183`)

3.1.5

==================

Bugs fixed
----------

* Conversion from C++ strings longer than ``PY_SSIZE_T_MAX`` did not validate the length.

* Some non-Limited API code was incorrectly used in generated header files.
(Github issue :issue:`7157`)

* Optimised unpacking of Python integers in expressions uses a slightly safer scheme.
(Github issue :issue:`7134`)

* Empty return statements were not always reported when tracing.
(Github issue :issue:`7022`)

* Value conversion errors when tracing C return statements no longer fail the trace
but fall back to reporting ``None`` returns instead.
(Github issue :issue:`6503`)

3.1.4

==================

Features added
--------------

* Declarations for the new ``PyUnstable_*()`` refcounting C-API functions in Py3.14 were added.

Bugs fixed
----------

* The monitoring code could crash on tracing.
(Github issue :issue:`7050`)

* Initialising the monitoring code could fail with a CPython exception.
See https://github.com/nedbat/coveragepy/issues/1790#issuecomment-3257410149

* Optimised integer shifting triggered undefined behaviour in C.
(Github issue :issue:`7089`)

* Deallocating objects that inherit from external types defined in pxd files
could run into an infinite loop.
(Github issue :issue:`7143`)

* A reference to metaclasses could be leaked on instantiation.
(Github issue :issue:`7130`)

* (Unlikely) error handling during empty builtin container tests was ineffective.
(Github issue :issue:`7190`)

* Generated ``*_api.h`` files used potentially unknown Cython configuration macros.
(Github issue :issue:`7108`)

* ``cythonize()`` avoids parallel compiler runs on systems using ``spawn()`` in multiprocessing.
Patch by Marcel Bargull.  (Github issue :issue:`3262`)

* The ``cython.ufunc``  decorator was missing in type checker stubs.
Patch by jayClean.  (Github issue :issue:`7109`)

3.1.3

==================

Bugs fixed
----------

* Some method calls with 0 or 1 argument failed to use ``PyObject_VectorCallMethod()``.

* Walrus assignments of literal Python integers could generate invalid C code.
(Github issue :issue:`6989`)

* ``cython.pythread_type_lock`` (also used as fallback for ``cython.pymutex``)
could stall on heavily contended locks.
(Github issue :issue:`6999`)

* C string arrays (not pointers) always coerced to the Python default string type,
even on explicit casts to other string types.
(Github issue :issue:`7020`)

* Unterminated ``\N{}`` character escapes in strings could unrail the parser.
(Github issue :issue:`7056`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* Some Unicode letters were not recognised as lexically valid name parts.
(Github issue :issue:`7059`)

* Compatibility with PyPy3.8 was lost by accident.

* The Linux binary wheels of 3.1.2 used SSSE3 CPU instructions which are not available on some CPUs.
(Github issue :issue:`7038`)

3.1.2

==================

Bugs fixed
----------

* Attribute lookups failed on the ``bool`` builtin type.
(Github issue :issue:`6905`)

* Type checks on or-ed union types could incorrectly return false.
(Github issue :issue:`6420`)

* Negative list indexing could accidentally wrap around twice in PyPy and the Limited API.

* Iterating over literal sequences with starred (unpacked) items could infer a wrong
type for the loop variable and fail to assign the values.
(Github issue :issue:`6924`)

* Calls to C functions taking exception types failed to check for a `None` argument.
(Github issue :issue:`6420`)

* Fused functions had an incorrect ``__module__`` attribute.
(Github issue :issue:`6897`)

* The type of Cython implemented functions had an incorrect ``__module__`` attribute.
(Github issue :issue:`6841`)

* Errors while indexing into ``bytearray`` or ``str`` in ``nogil`` sections could crash.
(Github issue :issue:`6947`)

* ``bytearray.append()`` could silently accept some invalid character numbers.

* The C++11 ``&lt;type_traits&gt;`` header was included regardless of the C++ version.
(Github issue :issue:`6896`)

* ``PyDict_GetItemStringRef()`` was accidentally used in older Limited API versions.
(Github issue :issue:`6914`)

* ``abort()`` was used but not always available in the Limited API.
(Github issue :issue:`6918`)

* Some dependencies were missing from the ``depfile``.
(Github issue :issue:`6938`)

* Embedded function signatures were not always separated from the existing docstring.
(Github issue :issue:`6904`)

* ``numpy.math`` was missing from ``Cython/Includes/`` and could not be cimported.
(Github issue :issue:`6859`)

* Some tests were adapted for NumPy 2.x.
(Github issue :issue:`6898`)

* Some C compiler warnings were fixed.
(Github issue :issue:`6870`)

* ``Cython.Build`` was not officially exposing the ``cythonize`` function.
(Github issue :issue:`6934`)

3.1.1

==================

Bugs fixed
----------

* A reference leak in the async delegation code was fixed.
(Github issues :issue:`6850`, :issue:`6878`)

* Conditional if-else expressions mixing Python and C (numeric) types could end up
inferring an overly tight result type, thus leading to unexpected type conversions,
runtime exceptions on assignment, or incorrect &quot;temporary assignment&quot; compile errors.
(Github issue :issue:`6854`)

* Some Limited API issues were resolved.
(Github issue :issue:`6862`)

* Large C ``long long`` values could be truncated when passed into PyPy.
(Github issue :issue:`6890`)

* ``callable()`` incorrectly reported ``False`` in PyPy for classes with metaclasses.
Patch by Anatolii Aniskovych. (Github issue :issue:`6892`)

* The signature of fused functions was no longer introspectable in Cython 3.1.0.
(Github issue :issue:`6855`)

* Coroutines could generate invalid C with line tracing enabled.
(Github issue :issue:`6865`)

* Code using ``complex()`` could generate invalid C code missing type declarations.
(Github issue :issue:`6860`)

* Code using e.g. ``list[int | None]``  outside of variable/argument annotations failed to compile.
(Github issue :issue:`6856`)

* Code using ctuples in a ``const`` context could generate invalid C.
(Github issue :issue:`6864`)

* Accessing special methods on cpdef enums failed to compile.

* Some C compiler warnings were resolved.
Patches by Daniel Larraz.  (Github issues :issue:`6876`, :issue:`3172`, :issue:`6873`, :issue:`6877`)

* Re-establish support for PyPy 3.8.
(Github issue :issue:`6867`)

3.1.0

==========================

Features added
--------------

* Support for freethreading builds of CPython 3.13 was added.
It comes with a new directive ``freethreading_compatible=True`` to mark modules as
free-threading compatible (``Py_mod_gil``).

https://github.com/cython/cython/issues?q=label%3A%22nogil+CPython%22

Patches by Lysandros Nikolaou and Nathan Goldbaum.  (Github issue :issue:`6162`)

* Support for monitoring Cython modules via `sys.monitoring` in CPython 3.13+ was added.
For coverage reporting, this needs to be disabled with `-DCYTHON_USE_SYS_MONITORING=0`
as long as `coverage.py` does not support `sys.monitoring` for coverage plugins.
(Github issue :issue:`6144`)

* Many issues with the Limited C-API were resolved.
It is now sufficient to define the macro ``Py_LIMITED_API`` to activate the support.

https://github.com/cython/cython/issues?q=label%3A%22limited+api%22

* Support for GraalPython was improved (but is still incomplete).

* Several issues with the gdb support were resolved.
Patches by Kent Slaney.  (Github issues :issue:`5955`, :issue:`5948`)

* ``typing.Union[SomeType, None]`` and ``SomeType | None`` are now understood and mean
the same as ``typing.Optional[SomeType]``, allowing ``None`` in type checks.
(Github issue :issue:`6254`)

* ``cython.const[]`` and ``cython.volatile[]`` are now available as type modifiers in Python code.
(Github issue :issue:`5728`)

* ``cython.pointer[SomeCType]`` can now be used to define pointer types in Python type annotations.
(Github issue :issue:`5071`)

* Several improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`4425`)

* Function calls now use the PEP-590 Vectorcall protocol, even when passing keyword arguments.
(Github issues :issue:`5804`)

* Coroutines now use the ``am_send`` slot function instead of going through a Python ``.send()`` call.
This has been backported for Python 3.7 - 3.9.
(Github issues :issue:`4585`)

* ``__set_name__`` is called when assigning to class attributes.
(Github issue :issue:`6179`)

* Most builtin methods now provide their return type for type inference.
(Github issues :issue:`4829`, :issue:`5865`, :issue:`6412`)

* Method calls on builtin literal values are evaluated at compile time, if applicable.
(Github issue :issue:`6383`)

* The Python ``int`` type now maps directly to ``PyLong`` and is inferred accordingly.
(Github issue :issue:`4237`)

* Integer operations on known ``int`` types are faster.
(Github issue :issue:`5785`)

* f-strings are faster in some cases.
(Github issues :issue:`5866`, :issue:`6342`, :issue:`6383`)

* ``divmod()`` is faster on C ``int``.
Patch by Tong He.  (Github issue :issue:`6073`)

* ``dict.pop()`` is faster in some cases.
(Github issue :issue:`5911`)

* ``.isprintable()`` is optimised for Unicode characters.
(Github issue :issue:`3277`)

* ``x in ()`` and similar tests against empty constant sequences (e.g. in generated code)
are now discarded if they have no side-effects.
(Github issue :issue:`6288`)

* Constant (non-GC) Python objects are no longer traversed with ``Py_VISIT()`` during GC runs.
(Github issue :issue:`6277`)

* C++ classes implemented in Cython can now use method overloading.
Patch by samaingw.  (Github issue :issue:`3235`)

* Assigning a Python container to a C++ vector now makes use of ``__length_hint__``
to avoid reallocations.
Patch by Denis Lukianov.  (Github issue :issue:`6077`)

* The C++11 ``emplace*`` methods were added to ``libcpp.deque``.
Patch by Somin An.  (Github issue :issue:`6159`)

* ``cpython.time`` was updated and extended for Python 3.13.
(Github issue :issue:`6187`)

* Dataclasses support the ``match_args`` option.
(Github issue :issue:`5381`)

* Threading in parallel sections can now be disabled with a new ``use_threads_if`` condition.
(Github issue :issue:`5919`)

* New options ``warn.deprecated.DEF`` and ``warn.deprecated.IF`` can silence the deprecation warnings.
Patch by Eric Larson.  (Github issue :issue:`6243`)

* ``cygdb`` shows more helpful output for some objects.
Patch by Kent Slaney.  (Github issue :issue:`5958`)

* Bazel build support for improved.
Patch by mering.  (Github issue :issue:`6452`)

* The parser was updated for Unicode 15.1 (as provided by CPython 3.13b4).

Bugs fixed
----------

* C functions used different start lines and columns for error reporting and tracing
than Python functions.  They now use the line and column of their first decorator
or (if none) their definition line, as in Python.
(Github issue :issue:`6366`)

* Dataclasses did not handle default fields without init value correctly.
(Github issue :issue:`5858`)

* Implementing a special method based on another could lead to infinite recursion.
(Github issue :issue:`5863`)

* The ``__class__`` cell variable in methods was not always working as in Python.
Initial patch by Tom Keefe.  (Github issue :issue:`2912`)

* Lambda functions had no code objects. Their signature can now be introspected.
(Github issue :issue:`2983`)

* Subtyping `complex` as extension type could fail.
(Github issue :issue:`6346`)

* ``hasattr()`` now propagates exceptions that occur during lookup.
(Github issue :issue:`6269`)

* The base type of extension heap types is now traversed during GC runs in Py3.9+.
(Github issue :issue:`4193`)

* The Python ``&amp;`` operator could touch invalid memory with certain ``0`` values in Python &lt;= 3.10.
Patch by Michael J. Sullivan.  (Github issue :issue:`4193`)

* Exception values were not always recognised as equal at compile time.
(Github issue :issue:`5709`)

* Running Cython in different Python versions could generate slightly different C code
due to differences in the builtins.
(Github issue :issue:`5591`)

* The `common_include_dir` feature used different file paths in the C code on Windows and Posix.
It now uses forward slashes as directory separator consistently.
(Github issue :issue:`6355`)

* File paths in the C code are now relative to the build directory.
Patch by Oscar Benjamin.  (Github issue :issue:`6341`)

* depfiles now use relative paths whenever possible.
Patch by Loïc Estève.  (Github issue :issue:`6345`)

* The ``-a`` option in the IPython magic no longer copies the complete HTML document
into the notebook but only a more reasonable content snippet.
Patch by Min RK.  (Github issue :issue:`5760`)

* Uselessly referring to C enums (not enum values) as Python objects is now rejected.
Patch by Vyas Ramasubramani.  (Github issue :issue:`5638`)

* Cython no longer acquires the GIL during in-place assignments to C attributes in nogil sections.
Patch by Mads Ynddal.  (Github issue :issue:`6407`)

* Several C++ warnings about ``char*`` casts were resolved.
(Github issues :issue:`5515`, :issue:`5847`)

* C++ undefined behaviour was fixed in an error handling case.
(Github issue :issue:`5278`)

* Dict assignments to struct members with reserved C/C++ names could generate invalid C code.

* The PEP-479 implementation could raise a visible ``RuntimeError`` without
a trace of the original ``StopIteration``.
(Github issue :issue:`5953`)

* A crash was fixed when assigning a zero-length slice to a memoryview.
Patch by Michael Man.  (Github issue :issue:`6227`)

* Conditionally assigning to variables with the walrus operator could crash.
(Github issue :issue:`6094`)

* Unterminated string literals could lock up the build in an infinite loop.
(Github issue :issue:`5977`)

* Exporting C functions uses better platform compatible code.
(Github issue :issue:`4683`)

* The shebang in ``libpython.py`` was incorrect.
Patch by Luke Hamburg.  (Github issue :issue:`6439`)

* Cython now uses `SHA-256` instead of `SHA-1` for caching etc. as the latter may not be
available on all Python installations.
(Github issue :issue:`6354`)

Other changes
-------------

* Support for Python 2.7 - 3.7 was removed, along with large chunks of legacy code.
(Github issue :issue:`2800`)

* The pxd files ``cpython.int``, ``cpython.cobject``, ``cpython.oldbuffer`` and ``cpython.string``
were removed as they refer to C-API declarations that are only in Python 2.x.
(Github issue :issue:`5870`)

* The generated C code now requires a C99 compatible C compiler.

* ``language_level=3`` is now the default.
``language_level=3str`` has become a legacy alias.
(Github issue :issue:`5827`)

* The Py2 types ``unicode`` and ``basestring`` are now deprecated and have become aliases
of the ``str`` type.
(Github issue :issue:`6374`)

* Docstrings now strip their leading whitespace according to PEP-257.
Patch by Lawrence Mitchell.  (Github issue :issue:`6241`)

* Type checkers should have it easier to find and validate Cython types in .py files.
(Github issue :issue:`4327`)

* The previously shipped NumPy C-API declarations (``cimport numpy``) were removed.
NumPy has been providing version specific declarations for several versions now.
(Github issue :issue:`5842`)

* Usages of the outdated ``WITH_THREAD`` macro guard were removed.
(Github issue :issue:`5812`)

* The options for showing the C code line in Python exception stack traces were cleaned up.
Previously, disabling the option with the ``CYTHON_CLINE_IN_TRACEBACK`` macro did not
reduce the code overhead of the feature, and the ``c_line_in_traceback`` compile option
was partly redundant with the C macro switches and lead to warnings about unused code.
Since this is considered mostly a debug feature, the new default is that it is _disabled_
to avoid code and runtime overhead.  It can be enabled by setting the C macro to 1, and
a new macro ``CYTHON_CLINE_IN_TRACEBACK_RUNTIME`` was added that controls the runtime
configurable setting if the feature is enabled, which was previously only available
through the compile option.  The compile option is now deprecated (but still available),
and users should migrate to using the two C macros only.
(Github issue :issue:`6036`)

* Includes all fixes as of Cython 3.0.11 (but generates C99 code in some places).

3.0.12

===================

Bugs fixed
----------

* Release 3.0.11 introduced some incorrect ``noexcept`` warnings.
(Github issue :issue:`6335`)

* Conditional assignments to variables using the walrus operator could crash.
(Github issue :issue:`6094`)

* Dict assignments to struct members with reserved C names could generate invalid C code.

* Fused ctuples with the same entry types but different sizes could fail to compile.
(Github issue :issue:`6328`)

* In Py3, `pyximport` was not searching `sys.path` when looking for importable source files.
(Github issue :issue:`5615`)

* Using `&amp; 0` on integers produced with `int.from_bytes()` could read invalid memory on Python 3.10.
(Github issue :issue:`6480`)

* Modules could fail to compile in PyPy 3.11 due to missing CPython specific header files.
Patch by Matti Picus.  (Github issue :issue:`6482`)

* Minor fix in C++ ``partial_sum()`` declaration.

3.0.11

===================

Features added
--------------

* The C++11 ``emplace*`` methods were added to ``libcpp.deque``.
Patch by Somin An.  (Github issue :issue:`6159`)

Bugs fixed
----------

* The exception check value of functions declared in pxd files was not always applied in 3.0.10.
(Github issue :issue:`6122`)

* A crash on exception deallocations was fixed.
(Github issue :issue:`6022`)

* A crash was fixed when assigning a zero-length slice to a memoryview.
Patch by Michael Man.  (Github issue :issue:`6227`)

* ``libcpp.optional.value()`` could crash if it raised a C++ exception.
Patch by Alexander Condello.  (Github issue :issue:`6190`)

* The return type of ``str()`` was mishandled, leading to crashes with ``language_level=3``.
(Github issue :issue:`6166`)

* ``bytes.startswith/endswith()`` failed for non-bytes substrings (e.g. ``bytearray``).
(Github issue :issue:`6168`)

* Fused ctuples crashed Cython.
(Github issue :issue:`6068`)

* A compiler crash was fixed when using extension types in fused types.
(Github issue :issue:`6204`)

* The module cleanup code was incorrect for globally defined memory view slices.
(Github issue :issue:`6276`)

* Some adaptations were made to enable compilation in Python 3.13.
(Github issues :issue:`5997`, :issue:`6182`, :issue:`6251`)

Links

PyPI: https://pypi.org/project/cython
Changelog: https://data.safetycli.com/changelogs/cython/
Homepage: https://cython.org/

Update cython from 3.0.10 to 3.2.4

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pyup-bot mentioned this pull request Jan 4, 2026

Update cython to 3.2.3 #2405

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Update cython to 3.2.4#2420
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pyup-bot commented Jan 4, 2026

3.2.4

3.2.3

3.2.2

3.2.1

3.2.0

3.2.0b3

3.2.0b2

3.2.0b1

3.1.8

3.1.7

3.1.6

3.1.5

3.1.4

3.1.3

3.1.2

3.1.1

3.1.0

3.0.12

3.0.11

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