Release notes from pybind11

Version 3.0.2

2026-02-17T04:45:48Z

New Features:

Added helper functions to py::array that return shape and strides as std::span when available.
#5974

Bug fixes:

Added fallback locking for Python 3.13t where PyCriticalSection_BeginMutex is unavailable.
#5981
Fixed race condition in py::make_key_iterator with free-threaded Python.
#5971
MSVC 19.16 and earlier were blocked from using std::launder due to internal compiler errors.
#5968
Internals destructors were updated to check the owning interpreter before clearing Python objects.
#5965
Internals shutdown handling was refined in two iterations before release: an initial finalization-time cleanup was followed by a safety adjustment to avoid late-shutdown py::cast segfaults.
#5958
#5972
Fixed ambiguous str(handle) construction for object-derived types like kwargs or dict by templatizing the constructor with SFINAE.
#5949
Fixed concurrency consistency for internals_pp_manager under multiple-interpreters.
#5947
Fixed MSVC LNK2001 in C++20 builds when /GL (whole program optimization) is enabled.
#5939
Added per-interpreter storage for gil_safe_call_once_and_store to make it safe under multi-interpreters.
#5933
A workaround for a GCC -Warray-bounds false positive in argument_vector was added.
#5908
Corrected a mistake where support for __index__ was added, but the type hints did not reflect acceptance of SupportsIndex objects. Also fixed a long-standing bug: the complex-caster did not accept __index__ in convert mode.
#5891
Fixed *args/**kwargs return types. Added type hinting to py::make_tuple.
#5881
Fixed compiler error in type_caster_generic when casting a T implicitly convertible from T*.
#5873
Updated py::native_enum bindings to unregister enum types on destruction, preventing a use-after-free when returning a destroyed enum instance.
#5871
Fixed undefined behavior that occurred when importing pybind11 modules from non-main threads created by C API modules or embedded python interpreters.
#5870
Fixed dangling pointer in internals::registered_types_cpp_fast.
#5867
Added support for std::shared_ptr<T> when loading module-local or conduit types from other modules.
#5862
Fixed thread-safety issues if types were concurrently registered while get_local_type_info() was called in free threaded Python.
#5856
Fixed py::float_ casting and py::int_ and py::float_ type hints.
#5839
Fixed two smart_holder bugs in shared_ptr and unique_ptr adoption with multiple/virtual inheritance:
- shared_ptr to-Python caster was updated to register the correct subobject pointer (fixes #5786).
- unique_ptr adoption was updated to own the proper object start while aliasing subobject pointers for registration, which fixed MSVC crashes during destruction.
  #5836
Constrained accessor::operator= templates to avoid obscuring special members.
#5832
Fixed crash that can occur when finalizers acquire and release the GIL.
#5828
Fixed compiler detection in pybind11/detail/pybind11_namespace_macros.h for clang-cl on Windows, to address warning suppression macros.
#5816
Fixed compatibility with CMake policy CMP0190 by not always requiring a Python interpreter when cross-compiling.
#5829
Added a static assertion to disallow keep_alive and call_guard on properties.
#5533

Internal:

CMake policy limit was set to 4.1.
#5944
Improved performance of function calls between Python and C++ by switching to the "vectorcall" calling protocol.
#5948
Many C-style casts were replaced with C++-style casts.
#5930
Added cast_sources abstraction to type_caster_generic.
#5866
Improved the performance of from-Python conversions of legacy pybind11 enum objects bound by py::enum_.
#5860
Reduced size overhead by deduplicating functions' readable signatures and type information.
#5857
Used new Python 3.14 C APIs when available.
#5854
Improved performance of function dispatch and type casting by porting two-level type info lookup strategy from nanobind.
#5842
Updated .gitignore to exclude __pycache__/ directories.
#5838
Changed internals to use thread_local instead of thread_specific_storage for increased performance.
#5834
Reduced function call overhead by using thread_local for loader_life_support when possible.
#5830
Removed heap allocation for the C++ argument array when dispatching functions with 6 or fewer arguments.
#5824

Documentation:

Fixed docstring for long double complex types to use numpy.clongdouble instead of the deprecated numpy.longcomplex (removed in NumPy 2.0).
#5952
The "Supported compilers" and "Supported platforms" sections in the main README.rst were replaced with a new "Supported platforms & compilers" section that points to the CI test matrix as the living source of truth.
#5910
Fixed documentation formatting.
#5903
Updated upgrade notes for py::native_enum.
#5885
Clarified in the docs to what extent bindings are global.
#5859

Tests:

Fixed deadlock in a free-threading test by releasing the GIL while waiting on synchronization.
#5973
Calls to env.deprecated_call() were replaced with direct calls to pytest.deprecated_call().
#5893
Updated pytest configuration to use log_level instead of log_cli_level.
#5890

CI:

Added CI tests for windows-11-arm with clang/MSVC (currently python 3.13), windows-11-arm with clang/mingw (currently python 3.12).
#5932
These clang-tidy rules were added: readability-redundant-casting, readability-redundant-inline-specifier, readability-redundant-member-init
#5924
Replaced deprecated macos-13 runners with macos-15-intel in CI.
#5916
Restored runs-on: windows-latest in CI.
#5835

Version 3.0.1

2025-08-22T20:05:37Z

Bug fixes:

Fixed compilation error in type_caster_enum_type when casting pointer-to-enum types. Added pointer overload to handle dereferencing before enum conversion. #5776
Implement binary version of make_index_sequence to reduce template depth requirements for functions with many parameters. #5751
Subinterpreter-specific exception handling code was removed to resolve segfaults. #5795
Fixed issue that caused PYBIND11_MODULE code to run again if the module was re-imported after being deleted from sys.modules. #5782
Prevent concurrent creation of sub-interpreters as a workaround for stdlib concurrency issues in Python 3.12. #5779
Fixed potential crash when using cpp_function objects with sub-interpreters. #5771
Fixed non-entrant check in implicitly_convertible(). #5777
Support C++20 on platforms that have older c++ runtimes. #5761
Fix compilation with clang on msys2. #5757
Avoid nullptr dereference warning with GCC 13.3.0 and python 3.11.13. #5756
Fix potential warning about number of threads being too large. #5807

Fix gcc 11.4+ warning about serial compilation using CMake. #5791

Documentation:

Improve buffer_info type checking in numpy docs. #5805
Replace robotpy-build with semiwrap in the binding tool list. #5804
Show nogil in most examples. #5770
Fix py::trampoline_self_life_support visibility in docs. #5766

Tests:

Avoid a spurious warning about DOWNLOAD_CATCH being manually specified. #5803
Fix an IsolatedConfig test. #5768

CI:

Add CI testing for Android. #5714

Internal:

Rename internal variables to avoid the word slots (reads better). #5793

Version 3.0.0

2025-07-18T16:48:43Z

Pybind11 3.0 includes an ABI bump, the first required bump in many years on Unix (Windows has had required bumps more often). This release contains the smart-holder branch, multi-phase init and subinterpreter support, py::native_enum, an interface to warnings, typing improvements, and more. CMake now defaults to FindPython mode. Please check our upgrade guide for more info on upgrading!

Support for Python 3.14, 3.14t, GraalPy, and PyPy 3.11 has been added, while legacy support for Python 3.7, PyPy 3.8/3.9, and CMake <3.15 has been removed. Most deprecated features have been kept for this release, but anything producing a warning in 3.0 may be removed in a future 3.x version. We also now have a deprecation page.

New Features:

The smart_holder branch has been merged, enabling py::class_<T, py::smart_holder>, which handles two-way conversion with std::unique_ptr<T> and std::shared_ptr<T> (simultaneously), disowning a Python object being passed to std::unique_ptr<T>, trampoline objects, and std::enable_shared_from_this. #5542
- Added support for std::shared_ptr<const T> in py::init() when using py::smart_holder, complementing existing support for std::unique_ptr<const T>. #5731
- Support const-only smart pointers. #5718
- Eliminate cross-DSO RTTI reliance from trampoline_self_life_support functionality, smart_holder deleter detection, and other smart_holder bookkeeping. Resolves platform-specific issues on macOS related to cross-DSO dynamic_cast and typeid mismatches. #5728 (replaces #5700)
Changed PYBIND11_MODULE macro implementation to perform multi-phase module initialization (PEP 489) behind the scenes. #5574 and avoid destruction #5688
Support for sub-interpreters (both isolated (with separate GILs) and legacy (with a global GIL). Add the py::multiple_interpreters::per_interpreter_gil() tag (or, py::multiple_interpreters::shared_gil() for legacy interpreter support) to PYBIND11_MODULE calls (as the third parameter) to indicate that a module supports running with sub-interpreters. #5564
- Rename macro PYBIND11_SUBINTERPRETER_SUPPORT -> PYBIND11_HAS_SUBINTERPRETER_SUPPORT to meet naming convention. #5682
- Allow subinterpreter support to be disabled if defined to 0. This is mostly an emergency workaround, and is not exposed in CMake. #5708 and #5710
- Modify internals pointer-to-pointer implementation to not use thread_local (better iOS support). #5709
- Support implementations without subinterpreter support. #5732
Changed PYBIND11_EMBEDDED_MODULE macro implementation to perform multi-phase module initialization (PEP 489) behind the scenes and to support py::mod_gil_not_used(), py::multiple_interpreters::per_interpreter_gil() and py::multiple_interpreters::shared_gil(). #5665 and consolidate code #5670
Added API in pybind11/subinterpreter.h for embedding sub-intepreters (requires Python 3.12+). #5666
py::native_enum was added, for conversions between Python's native (stdlib) enum types and C++ enums. #5555
- Add class doc string to py::native_enum. #5617
- Fix signature for functions with a native_enum in the signature. #5619
Support py::numpy_scalar<> / py::make_scalar() for NumPy types. #5726
A py::release_gil_before_calling_cpp_dtor option (for py::class_) was added to resolve the long-standing issue #1446. #5522
Add dtype::normalized_num and dtype::num_of. #5429
Add support for array_t<handle> and array_t<object>. #5427
Added py::warnings namespace with py::warnings::warn and py::warnings::new_warning_type that provides the interface for Python warnings. #5291
stl.h list|set|map_caster were made more user friendly: it is no longer necessary to explicitly convert Python iterables to tuple(), set(), or map() in many common situations. #4686
The array_caster in pybind11/stl.h was enhanced to support value types that are not default-constructible. #5305
pybind11/conduit/pybind11_platform_abi_id.h was factored out, to maximize reusability of PYBIND11_PLATFORM_ABI_ID (for other Python/C++ binding systems). Separately, a note was added to explain that the conduit feature only covers from-Python-to-C++ conversions. #5375 | #5740
Added support for finding pybind11 using pkgconf distributed on pypi. #5552
Support --extension-suffix on the pybind11 command. #5360
Add semi-public API: pybind11::detail::is_holder_constructed and update example for pybind11::custom_type_setup in documentation. #5669
Added py::scoped_critical_section to support free-threaded mode. #5684 | #5706

New Features / fixes (typing):

Added option for different arg/return type hints to type_caster. Updated stl/filesystem to use correct arg/return type hints. Updated pybind11::typing to use correct arg/return type hints for nested types. #5450
Updated type hint for py::capsule to type.CapsuleType. #5567
Adds support for typing.SupportsInt and typing.SupportsFloat. Update Final to be narrower type hint. Make std::function match Callable type. Fix io_name bug in attr_with_type_hint. #5540
Rework of arg/return type hints to support .noconvert(). #5486
Add attr_with_type for declaring attribute types and Final, ClassVar type annotations. #5460
Allow annotate methods with py::pos_only when only have the self argument. Make arguments for auto-generated dunder methods positional-only. #5403
Added py::Args and py::KWArgs to enable custom type hinting of *args and **kwargs (see PEP 484). #5357
Switched to numpy.typing.NDArray and numpy.typing.ArrayLike. #5212
Use numpy.object_ instead of object. #5571
Fix module type hint. #5469
Fix Buffer type hint. #5662
Added support for collections.abc in type hints and convertible checks of STL casters and py::buffer. #5566
Fix typing and collections.abc type hint ambiguity. #5663
Add typing_extensions alternatives for all types that need them. #5693

Removals:

Remove support for pybind11 v2 internals versions (4, 5, 6). (The internals version number has been bumped for pybind11 v3.) #5512 | #5530
Remove make_simple_namespace (added in 2.8.0, deprecated in 2.8.1). #5597
Legacy-mode option PYBIND11_NUMPY_1_ONLY has been removed. #5595
Add a deprecation warning to .get_type (deprecated in pybind11 2.6 in 2020). #5596

Bug fixes:

Set __file__ on submodules. #5584. Except on embedded modules. #5650
pybind11-bound functions are now pickleable. #5580
Fix bug in attr_with_type_hint to allow objects to be in attr_with_type_hint. #5576
A -Wmaybe-uninitialized warning suppression was added in pybind11/eigen/matrix.h. #5516
PYBIND11_WARNING_POP was incorrectly defined as PYBIND11_PRAGMA(clang diagnostic push). #5448
PYBIND11_PLATFORM_ABI_ID (which is used in composing PYBIND11_INTERNALS_ID) was modernized to reflect actual ABI compatibility more accurately. #4953 | #5439
Fix buffer protocol implementation. #5407
Fix iterator increment operator does not skip first item. #5400
When getting or deleting an element in a container bound by bind_map, print the key in KeyError if it does not exist. #5397
pybind11::builtin_exception is now explicitly exported when linked to libc++. #5390
Allow subclasses of py::args and py::kwargs. #5381
Disable false-positive GCC 12 Bound Check warning. #5355
Update the dict when restoring pickles, instead of assigning a replacement dict. #5658
Properly define _DEBUG macro to 1 instead of defining it without value. #5639
Fix a missing time cast causing a compile error for newer ICC. #5621
Change the behavior of the default constructor of py::slice to be equivalent to :: in Python. #5620

Bug fixes and features (CMake):

Enable FindPython mode by default, with a COMPAT mode that sets some of the old variables to ease transition. #5553
Add an author warning that auto-calculated PYTHON_MODULE_EXTENSION may not respect SETUPTOOLS_EXT_SUFFIX during cross-compilation. #5495
Don't strip with CMAKE_BUILD_TYPE None. #5392
Fix an issue with NO_EXTRAS adding pybind11::windows_extras anyway. #5378
Fix issue with NEW/OLD message showing up. #5656
Use CMake's warnings as errors if available (CMake 3.24+). #5612
Add support for running pybind11's tests via presets in CMake 3.25+. #5655 and support --fresh. #5668
Experimental CMake support for Android. #5733
Presets now generate compile_commands.json. #5685

Bug fixes (free-threading):

Fix data race in free threaded CPython when accessing a shared static variable. #5494
A free-threading data race in all_type_info() was fixed. #5419
Added exception translator specific mutex used with try_translate_exceptions in the free-threaded build for internal locking. #5362

Internals:

Consolidated all PYBIND11_HAS_... feature macros into pybind11/detail/common.h to streamline backward compatibility checks and simplify internal refactoring. This change ensures consistent macro availability regardless of header inclusion order. #5647
pybind11/gil_simple.h was factored out from pybind11/gil.h, so that it can easily be reused. #5614
Use CPython macros to construct PYBIND11_VERSION_HEX. #5683

Documentation:

Improved reference_internal policy documentation. #5528
A new "Double locking, deadlocking, GIL" document was added. #5394
Add documenting for free-threading and subinterpreters.
#5659

Tests:

Download the final Catch2 2.x release if Catch download is requested. #5568
Explicitly used signed char for two numpy dtype tests. As seen when compiling using clang on Linux with the -funsigned-char flag. #5545
CI testing now includes -Wwrite-strings -Wunreachable-code -Wpointer-arith -Wredundant-decls in some jobs. #5523
Add nightly wheels to scientific-python's nightly wheelhouse. #5675
Expect free-threaded warning when loading a non-free-threaded module. #5680
Run pytest under Python devmode. #5715

New and removed platforms:

Support Python 3.14 (beta 1+). #5646
Added support for GraalPy Python implementation (https://github.com/oracle/graalpython). #5380
Support and test iOS in CI. #5705
Support for PyPy 3.11 added. #5508 And test in ci. #5534
Support for PyPy 3.8 and 3.9 was dropped. #5578
Support for Python 3.7 was removed. (Official end-of-life: 2023-06-27). #5191
Support for CMake older than 3.15 removed. CMake 3.15-4.0 supported. #5304 and fix regression #5691.
Use scikit-build-core for the build backend for the PyPI pybind11. The CMake generation has been moved to the sdist->wheel step. PYBIND11_GLOBAL_SDIST has been removed. #5598 and updated docs/ci. #5676
clang 20 tested and used for clang-tidy. #5692
Drop testing on MSVC 2019 (as it is being removed from GitHub). #5712
Support Windows C++20 and Linux C++23 in tests. #5707

Full Changelog: v3.0.0rc4...v3.0.0

Version 3.0.0 RC 4

2025-06-19T14:56:11Z

What's Changed

feat: numpy scalars by @henryiii in #5726
fix: TSan warning in sub-interpreter test by @b-pass in #5729
fix: add support for shared_ptr<const T> in py::init() with smart_holder by @rwgk in #5731
fix: add support for const-only smart pointers by @Rosdf in #5718
fix: android CMake support by @henryiii in #5733
fix: eliminate cross-DSO RTTI reliance in smart_holder functionality (for platforms like macOS). by @rwgk in #5728
fix: handle implementations without subinterpreter support by @msimacek in #5732
ci: avoid 3.13.4 on Windows by @henryiii in #5725
ci: check latest on 3.13 by @henryiii in #5734
ci: cibw update to 3.0.0rc2 by @henryiii in #5717
docs: Add documentation entry for warnings by @jiwaszki in #5356
tests: better test for const only smart ptr by @Rosdf in #5727
tests: run pytest under Python devmode by @XuehaiPan in #5715
chore(deps): bump pypa/cibuildwheel from 3.0.0rc2 to 3.0 in the actions group by @dependabot in #5721
chore(deps): bump requests from 2.32.3 to 2.32.4 in /docs by @dependabot in #5720
chore(deps): bump urllib3 from 2.2.2 to 2.5.0 in /docs by @dependabot in #5735
chore: prepare for 3.0.0rc4 by @henryiii in #5736

Important

This RC has an ABI bump. This is expected to be the last bump (and last RC) unless something comes up.

New Contributors

@Rosdf made their first contribution in #5718

Full Changelog: v3.0.0rc3...v3.0.0rc4

Version 3.0.0 RC 3

2025-06-05T16:21:59Z

This is another release candidate. See the changelog in the docs for the combined changelog; this is just the changes since RC 2:

fix(types): type hints from future python versions by @InvincibleRMC in #5693
fix: allow subinterpreters to be manually disabled by @henryiii in #5708
fix: follow rest of pybind11 closer with PYBIND11_HAS_SUBINTERPRETER_SUPPORT by @henryiii in #5710
fix: modify the internals pointer-to-pointer implementation to not use thread_local by @b-pass in #5709
fix: expose required symbol using clang by @petersteneteg in #5700
fix: handle null py::handle and add tests for py::scoped_critical_section by @XuehaiPan in #5706
ci: avoid brownout (and removal) of windows-2019 by @henryiii in #5712
ci: ios by @henryiii in #5705
ci: reduced runs on draft PRs by @henryiii in #5707
docs: prepare for RC 3 by @henryiii in #5713

Warning

Note our iOS support requires a cibuildwheel 3.0 beta currently, the cibuildwheel v3.0.0rc1 does not work.

Important

This RC has an ABI bump. We might need one more ABI bump before 3.0 final to improve the protection of our internals.

New Contributors

@petersteneteg made their first contribution in #5700

Full Changelog: v3.0.0rc2...v3.0.0rc3

Version 3.0.0 RC 2

2025-05-29T15:53:58Z

This is another release candidate. See the changelog in the docs for the combined changelog; this is just the changes since RC 1:

feat: scoped_critical_section by @henryiii in #5684
fix(cmake): regression in include guard by @henryiii in #5691
fix: don't destruct module objects in atexit by @b-pass in #5688
fix: prepare for 3.14 beta 2 by @henryiii in #5697
chore(cmake): add compile commands to preset by @henryiii in #5685
chore: bump maximum clang tested to 20 by @henryiii in #5692
chore: rename macro PYBIND11_SUBINTERPRETER_SUPPORT -> PYBIND11_HAS_SUBINTERPRETER_SUPPORT to meet naming convention by @XuehaiPan in #5682
chore: use CPython macros to construct PYBIND11_VERSION_HEX by @XuehaiPan in #5683
docs: more warnings about locking and the GIL by @henryiii in #5689
docs: update contributing/release guide a little by @henryiii in #5681
tests: always disable on the nogil build by @henryiii in #5701
tests: expect free-threaded import warnings by @henryiii in #5680
tests: skip some flaky gil tests on nogil by @henryiii in #5699

Full Changelog: v3.0.0rc1...v3.0.0rc2

Version 3.0.0 RC 1

2025-05-21T20:16:09Z

What's Changed

Since this is a large release, we are providing a release candidate to give projects time to test! We also now provide SPEC 4 nightly wheels. We are hoping to split up std.h; that work is approved to be added during the RC phase if it's ready in time. We expect the RC phase to last around a week.

New Features:

The smart_holder branch has been merged, enabling py::class_<T, py::smart_holder>, which handles two-way conversion
with std::unique_ptr<T> and std::shared_ptr<T> (simultaneously), disowning a Python object being passed to std::unique_ptr<T>, trampoline objects, and std::enable_shared_from_this. #5542
Changed PYBIND11_MODULE macro implementation to perform multi-phase module initialization (PEP 489) behind the scenes. #5574
Support for sub-interpreters (both isolated (with separate GILs) and legacy (with a global GIL). Add the
py::multiple_interpreters::per_interpreter_gil() tag (or, py::multiple_interpreters::shared_gil() for legacy interpreter
support) to PYBIND11_MODULE calls (as the third parameter) to indicate that a module supports running with sub-interpreters. #5564
Changed PYBIND11_EMBEDDED_MODULE macro implementation to perform multi-phase module initialization (PEP 489) behind the scenes and to support py::mod_gil_not_used(), py::multiple_interpreters::per_interpreter_gil() and py::multiple_interpreters::shared_gil(). #5665 and consolidate code #5670
Added API in pybind11/subinterpreter.h for embedding sub-intepreters (requires Python 3.12+). #5666
py::native_enum was added, for conversions between Python's native (stdlib) enum types and C++ enums. #5555
- Add class doc string to py::native_enum. #5617.
- Fix signature for functions with a native_enum in the signature. #5619
A py::release_gil_before_calling_cpp_dtor option (for py::class_) was added to resolve the long-standing issue #1446. #5522
Add dtype::normalized_num and dtype::num_of. #5429
Add support for array_t<handle> and array_t<object>. #5427
Added py::warnings namespace with py::warnings::warn and py::warnings::new_warning_type that provides the interface for
Python warnings. #5291
stl.h list|set|map_caster were made more user friendly: it is no longer necessary to explicitly convert Python iterables to tuple(),
set(), or map() in many common situations. #4686
The array_caster in pybind11/stl.h was enhanced to support value types that are not default-constructible. #5305
pybind11/conduit/pybind11_platform_abi_id.h was factored out, to maximize reusability of PYBIND11_PLATFORM_ABI_ID (for other Python/C++ binding systems). #5375
Added support for finding pybind11 using pkgconf distributed on pypi. #5552
Support --extension-suffix on the pybind11 command. #5360
Add semi-public API: pybind11::detail::is_holder_constructed and update example for pybind11::custom_type_setup in documentation. #5669

New Features / fixes (typing):

Added option for different arg/return type hints to type_caster. Updated stl/filesystem to use correct arg/return type hints. Updated pybind11::typing to use correct arg/return type hints for nested types. #5450
Updated type hint for py::capsule to type.CapsuleType. #5567
Adds support for typing.SupportsInt and typing.SupportsFloat. Update Final to be narrower type hint. Make std::function match Callable type. Fix io_name bug in attr_with_type_hint. #5540
Rework of arg/return type hints to support .noconvert(). #5486
Add attr_with_type for declaring attribute types and Final, ClassVar type annotations. #5460
Allow annotate methods with py::pos_only when only have the self argument. Make arguments for auto-generated dunder methods positional-only. #5403
Added py::Args and py::KWArgs to enable custom type hinting of *args and **kwargs (see PEP 484). #5357
Switched to numpy.typing.NDArray and numpy.typing.ArrayLike. #5212
Use numpy.object_ instead of object. #5571
Fix module type hint. #5469
Fix Buffer type hint. #5662
Added support for collections.abc in type hints and convertible checks of STL casters and py::buffer.
#5566
Fix typing and collections.abc type hint ambiguity. #5663

Removals:

Remove support for pybind11 v2 internals versions (4, 5, 6). (The internals version number has been bumped for pybind11 v3.) #5512 | #5530
Remove make_simple_namespace (added in 2.8.0, deprecated in 2.8.1). #5597
Legacy-mode option PYBIND11_NUMPY_1_ONLY has been removed. #5595
Add a deprecation warning to .get_type (deprecated in pybind11 2.6 in 2020). #5596

Bug fixes:

Set __file__ on submodules. #5584. Except on
embedded modules. #5650
pybind11-bound functions are now pickleable. #5580
Fix bug in attr_with_type_hint to allow objects to be in attr_with_type_hint. #5576
A -Wmaybe-uninitialized warning suppression was added in pybind11/eigen/matrix.h. #5516
PYBIND11_WARNING_POP was incorrectly defined as PYBIND11_PRAGMA(clang diagnostic push). #5448
PYBIND11_PLATFORM_ABI_ID (which is used in composing PYBIND11_INTERNALS_ID) was modernized to reflect actual ABI
compatibility more accurately. #4953 | #5439
Fix buffer protocol implementation. #5407
Fix iterator increment operator does not skip first item. #5400
When getting or deleting an element in a container bound by bind_map, print the key in KeyError if it does not exist. #5397
pybind11::builtin_exception is now explicitly exported when linked to libc++. #5390
Allow subclasses of py::args and py::kwargs. #5381
Disable false-positive GCC 12 Bound Check warning. #5355
fix: using __cpp_nontype_template_args instead of __cpp_nontype_template_parameter_class. #5330
Properly translate C++ exception to Python exception when creating Python buffer from wrapped object. #5324
Update the dict when restoring pickles, instead of assigning a replacement dict. #5658
Properly define _DEBUG macro to 1 instead of defining it without value. #5639
Fix a missing time cast causing a compile error for newer ICC. #5621
Change the behavior of the default constructor of py::slice to be equivalent to :: in Python. #5620

Bug fixes (CMake):

Enable FindPython mode by default, with a COMPAT mode that sets some of the old variables to ease transition. #5553
Add an author warning that auto-calculated PYTHON_MODULE_EXTENSION may not respect SETUPTOOLS_EXT_SUFFIX during cross-compilation. #5495
Don't strip with CMAKE_BUILD_TYPE None. #5392
Fix an issue with NO_EXTRAS adding pybind11::windows_extras anyway. #5378
Fix issue with NEW/OLD message showing up. #5656
Use CMake's warnings as errors if available (CMake 3.24+). #5612
Add support for running pybind11's tests via presets in CMake 3.25+. #5655 and support --fresh. #5668
Restructure venv support to support --fresh, make in build folder. #5668

Bug fixes (free-threading):

Fix data race in free threaded CPython when accessing a shared static variable. #5494
A free-threading data race in all_type_info() was fixed. #5419
Added exception translator specific mutex used with try_translate_exceptions in the free-threaded build for internal
locking. #5362

Internals:

Consolidated all PYBIND11_HAS_... feature macros into pybind11/detail/common.h to streamline backward compatibility checks and simplify internal refactoring. This change ensures consistent macro availability regardless of header inclusion order. #5647
pybind11/gil_simple.h was factored out from pybind11/gil.h, so that it can easily be reused. #5614

Documentation:

Improved reference_internal policy documentation. #5528
A new "Double locking, deadlocking, GIL" document was added. #5394
Adds an answer (FAQ) for "What is a highly conclusive and simple way to find memory leaks?". #5340
Add documenting for free-threading and subinterpreters. #5659

Tests:

Download the final Catch2 2.x release if Catch download is requested. #5568
Explicitly used signed char for two numpy dtype tests. As seen when compiling using clang on Linux with the -funsigned-char flag. #5545
Test PyPy3.11 in CI. #5534
CI testing now includes -Wwrite-strings -Wunreachable-code -Wpointer-arith -Wredundant-decls in some jobs. #5523
Add nightly wheels to scientific-python's nightly wheelhouse. #5675

New and removed platforms:

Support Python 3.14 (beta 1). #5646
Added support for GraalPy Python implementation (https://github.com/oracle/graalpython). #5380
Support for PyPy 3.11 added. #5508
Support for PyPy 3.8 and 3.9 was dropped. #5578
Support for Python 3.7 was removed. (Official end-of-life: 2023-06-27). #5191
Support for CMake older than 3.15 removed. CMake 3.15-4.0 supported. #5304
Use scikit-build-core for the build backend for the PyPI pybind11. The CMake generation has been moved to the sdist->wheel step.
PYBIND11_GLOBAL_SDIST has been removed. #5598 and updated
docs/ci. #5676

New Contributors

@varunagrawal made their first contribution in #5207
@wenqing made their first contribution in #5208
@rgommers made their first contribution in #5250
@teo-tsirpanis made their first contribution in #5263
@fred-sch made their first contribution in #5284
@pwdcd made their first contribution in #5308
@MarkusBauer made their first contribution in #4874
@ObeliskGate made their first contribution in #5314
@DWesl made their first contribution in #5326
@vnlitvinov made their first contribution in #5324
@BobbyRBruce made their first contribution in #5355
@vfdev-5 made their first contribution in #5362
@Hintay made their first contribution in #5378
@gentlegiantJGC made their first contribution in #5381
@sarlinpe made their first contribution in #5397
@francesco-ballarin made their first contribution in #5396
@J-M0 made their first contribution in #5448
@timohl made their first contribution in #5450
@jspricke made their first contribution in #5392
@nikulpatel3141 made their first contribution in #5360
@mattip made their first contribution in #5508
@daizhirui made their first contribution in #5516
@pganssle-google made their first contribution in #5545
@b-pass made their first contribution in #5574
@dyollb made their first contribution in #5617
@nsoblath made their first contribution in #5624

Full Changelog: v2.13.6...v3.0.0rc1

Version 2.13.6

2024-09-14T00:33:41Z

New Features:

A new self._pybind11_conduit_v1_() method is automatically added to all py::class_-wrapped types, to enable type-safe interoperability between different independent Python/C++ bindings systems, including pybind11 versions with different PYBIND11_INTERNALS_VERSION's. Supported on pybind11 2.11.2, 2.12.1, and 2.13.6+. #5296

Bug fixes:

Using __cpp_nontype_template_args instead of __cpp_nontype_template_parameter_class. #5330
Properly translate C++ exception to Python exception when creating Python buffer from wrapped object. #5324

Documentation:

Adds an answer (FAQ) for "What is a highly conclusive and simple way to find memory leaks?". #5340

Version 2.12.1

2024-09-13T22:27:56Z

New Features:

A new self._pybind11_conduit_v1_() method is automatically added to all py::class_-wrapped types, to enable type-safe interoperability between different independent Python/C++ bindings systems, including pybind11 versions with different PYBIND11_INTERNALS_VERSION's. Supported on pybind11 2.11.2, 2.12.1, and 2.13.6+. #5296

Version 2.11.2

2024-09-13T22:33:10Z

New Features:

A new self._pybind11_conduit_v1_() method is automatically added to all py::class_-wrapped types, to enable type-safe interoperability between different independent Python/C++ bindings systems, including pybind11 versions with different PYBIND11_INTERNALS_VERSION's. Supported on pybind11 2.11.2, 2.12.1, and 2.13.6+. #5296