Version 2.13.6

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

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

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 2.13.5

Bug fixes:

• Fix includes when using Windows long paths (\\?\ prefix). #5321
• Support -Wpedantic in C++20 mode. #5322
• Fix and test <ranges> support for py::tuple and py::list. #5314

Version 2.13.4

Bug fixes:

• Fix paths with spaces, including on Windows. (Replaces regression from #5302) #4874

Documentation:

• Remove repetitive words. #5308

Full Changelog: v2.13.3...v2.13.4

Version 2.13.3

Bug fixes:

• Quote paths from pybind11-config #5302
• Fix typo in Emscripten support when in config mode (CMake) #5301

Full Changelog: v2.13.2...v2.13.3

Version 2.13.2

New Features:

• A pybind11::detail::type_caster_std_function_specializations feature was added, to support specializations for std::function's with return types that require custom to-Python conversion behavior (to primary use case is to catch and convert exceptions). #4597

Changes:

• Use PyMutex instead of std::mutex for internal locking in the free-threaded build. #5219
• Add a special type annotation for C++ empty tuple. #5214
• When compiling for WebAssembly, add the required exception flags (CMake 3.13+). #5298

Bug fixes:

• Make gil_safe_call_once_and_store thread-safe in free-threaded CPython. #5246
• A missing #include <algorithm> in pybind11/typing.h was added to fix build errors (in case user code does not already depend on that include). #5208
• Fix regression introduced in #5201 for GCC<10.3 in C++20 mode. #5205
• Remove extra = when assigning flto value in the case for Clang in CMake. #5207

Tests:

• Adding WASM testing to our CI (Pyodide / Emscripten via scikit-build-core). #4745
• clang-tidy (in GitHub Actions) was updated from clang 15 to clang 18. #5272

Full Changelog: v2.13.1...v2.13.2

Version 2.13.1

New Features:

• Add support for Typing.Callable[..., T]. #5202

Bug fixes:

• Avoid aligned allocation in free-threaded build in order to support macOS versions before 10.14. #5200

Version 2.13.0

New Features:

• Support free-threaded CPython (3.13t). Add py::mod_gil_not_used() tag to indicate if a module supports running with the GIL disabled. #5148
• Support for Python 3.6 was removed. (Official end-of-life: 2021-12-23). #5177
• py::list gained a .clear() method. #5153
• Support for Union, Optional, type[T], typing.TypeGuard, typing.TypeIs, typing.Never, typing.NoReturn and typing.Literal was added to pybind11/typing.h. #5166 #5165 #5194 #5193 #5192
• In CMake, if PYBIND11_USE_CROSSCOMPILING is enabled, then CMAKE_CROSSCOMPILING will be respected and will keep pybind11 from accessing the interpreter during configuration. Several CMake variables will be required in this case, but can be deduced from the environment variable SETUPTOOLS_EXT_SUFFIX. The default (currently OFF) may be changed in the future. #5083

Bug fixes:

• A refcount bug (leading to heap-use-after-free) involving trampoline functions with PyObject * return type was fixed. #5156
• Return py::ssize_t from .ref_count() instead of int. #5139
• A subtle bug involving C++ types with unusual operator& overrides was fixed. #5189
• Support Python 3.13 with minor fix, add to CI. #5127
• Fix mistake affecting old cmake and old boost. #5149

Documentation:

• Build docs updated to feature scikit-build-core and meson-python, and updated setuptools instructions. #5168

Tests:

• Avoid immortal objects in tests. #5150

CI:

• Compile against Python 3.13t in CI.
• Use macos-13 (Intel) for CI jobs for now (will drop Python 3.7 soon). #5109
• Releases now have artifact attestations, visible at https://github.com/pybind/pybind11/attestations. #5196

Other:

• Some cleanup in preparation for 3.13 support. #5137
• Avoid a warning by ensuring an iterator end check is included in release mode. #5129
• Bump max cmake to 3.29. #5075
• Update docs and noxfile. #5071

Version 2.12.0

New Features:

• pybind11 now supports compiling for NumPy 2. Most code shouldn't change (see upgrade-guide-2.12 for details). However, if you experience issues you can define PYBIND11_NUMPY_1_ONLY to disable the new support for now, but this will be removed in the future. #5050
• pybind11/gil_safe_call_once.h was added (it needs to be included explicitly). The primary use case is GIL-safe initialization of C++ static variables. #4877
• Support move-only iterators in py::make_iterator, py::make_key_iterator, py::make_value_iterator. #4834
• Two simple py::set_error() functions were added and the documentation was updated accordingly. In particular, py::exception<>::operator() was deprecated (use one of the new functions instead). The documentation for py::exception<> was further updated to not suggest code that may result in undefined behavior. #4772

Bug fixes:

• Removes potential for Undefined Behavior during process teardown. #4897
• Improve compatibility with the nvcc compiler (especially CUDA 12.1/12.2). #4893
• pybind11/numpy.h now imports NumPy's multiarray and _internal submodules with paths depending on the installed version of NumPy (for compatibility with NumPy 2). #4857
• Builtins collections names in docstrings are now consistently rendered in lowercase (list, set, dict, tuple), in accordance with PEP 585. #4833
• Added py::typing::Iterator<T>, py::typing::Iterable<T>. #4832
• Render py::function as Callable in docstring. #4829
• Also bump PYBIND11_INTERNALS_VERSION for MSVC, which unlocks two new features without creating additional incompatibilities. #4819
• Guard against crashes/corruptions caused by modules built with different MSVC versions. #4779
• A long-standing bug in the handling of Python multiple inheritance was fixed. See PR #4762 for the rather complex details. #4762
• Fix bind_map with using declarations. #4952
• Qualify py::detail::concat usage to avoid ADL selecting one from somewhere else, such as modernjson's concat. #4955
• Use new PyCode API on Python 3.12+. #4916
• Minor cleanup from warnings reported by Clazy. #4988
• Remove typing and duplicate class_ for KeysView/ValuesView/ItemsView. #4985
• Use PyObject_VisitManagedDict() and PyObject_ClearManagedDict() on Python 3.13 and newer. #4973
• Update make_static_property_type() to make it compatible with Python 3.13. #4971

• Render typed iterators for make_iterator, make_key_iterator, make_value_iterator. #4876
• Add several missing type name specializations. #5073
• Change docstring render for py::buffer, py::sequence and py::handle (to Buffer, Sequence, Any). #4831
• Fixed base_enum.__str__ docstring. #4827
• Enforce single line docstring signatures. #4735
• Special 'typed' wrappers now available in typing.h to annotate tuple, dict, list, set, and function. #4259
• Create handle_type_name specialization to type-hint variable length tuples. #5051

• Setting PYBIND11_FINDPYTHON to OFF will force the old FindPythonLibs mechanism to be used. #5042
• Skip empty PYBIND11_PYTHON_EXECUTABLE_LAST for the first cmake run. #4856
• Fix FindPython mode exports & avoid pkg_resources if importlib.metadata available. #4941
• Python_ADDITIONAL_VERSIONS (classic search) now includes 3.12. #4909
• pybind11.pc is now relocatable by default as long as install destinations are not absolute paths. #4830
• Correctly detect CMake FindPython removal when used as a subdirectory. #4806
• Don't require the libs component on CMake 3.18+ when using PYBIND11_FINDPYTHON (fixes manylinux builds). #4805
• pybind11_strip is no longer automatically applied when CMAKE_BUILD_TYPE is unset. #4780
• Support DEBUG_POSFIX correctly for debug builds. #4761
• Hardcode lto/thin lto for Emscripten cross-compiles. #4642
• Upgrade maximum supported CMake version to 3.27 to fix CMP0148 warnings. #4786

Documentation:

• Small fix to grammar in functions.rst. #4791
• Remove upper bound in example pyproject.toml for setuptools. #4774

CI:

• CI: Update NVHPC to 23.5 and Ubuntu 20.04. #4764
• Test on PyPy 3.10. #4714

Other:

• Use Ruff formatter instead of Black. #4912
• An assert() was added to help Coverty avoid generating a false positive. #4817