fix(deps): update rust crate pyo3 to 0.29.0 [security] - #134

Details

PyO3 0.24.0 added optimized implementations of Iterator::nth and DoubleEndedIterator::nth_back for the BoundListIterator and BoundTupleIterator types. These implementations computed the target index using unchecked usize addition (index + n) before bounds-checking against the sequence length, then read the element via get_item_unchecked.

In nth methods, a sufficiently large n (combined with a non-zero internal index) could cause the addition to overflow and wrap around, producing a small "target index" that passed the bounds check and enabling reads at the front of the list or tuple of elements previously yielded by the iterator.

In nth_back methods, a sufficiently large n could cause underflow in a similar fashion, however would instead allow reads of arbitrary memory past the end of the list or tuple storage.

Severity

• CVSS Score: 8.7 / 10 (High)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/PyO3/pyo3/pull/6086
• https://rustsec.org/advisories/RUSTSEC-2026-0176.html
• https://github.com/advisories/GHSA-36hh-v3qg-5jq4

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Details

PyCFunction::new_closure (and the temporary new_closure_bound complement in the 0.21–0.22 series) required the supplied closure to be Send + 'static but not Sync. The resulting PyCFunction is a Python callable that can be invoked from any Python thread, which means the closure may be called concurrently from multiple threads, and needs a Sync bound to prevent possible data races.

The problem exists under all Python versions but is particularly vulnerable under the newer free-threaded Python variant, which do not have serial execution imposed by the Global Interpreter Lock. Under releases protected by the GIL, the ability to "detach" from the Python interpreter temporarily inside the closure (e.g. by Python::detach) makes it possible for interleaved and/or concurrent execution of various portions of the closure.

PyO3 0.29.0 added a Sync bound to close this thread-safety bug.

Severity

• CVSS Score: 6.3 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

References

• https://github.com/PyO3/pyo3/pull/6096
• https://github.com/PyO3/pyo3/releases/tag/v0.29.0
• https://rustsec.org/advisories/RUSTSEC-2026-0177.html
• https://github.com/advisories/GHSA-chgr-c6px-7xpp

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

v0.29.0

Compare Source

Packaging

• Support the new PEP 803 abi3t ABI with new abi3t and abi3t-py315 features. #​5807
• pyo3-macros-backend no longer depends on pyo3-build-config. #​5809
• Drop support for Python 3.13t (3.14t and above continue to be supported; CPython declared free-threading supported starting with Python 3.14). #​5865
• Drop support for Python 3.7. #​5912
• Extend range of supported versions of hashbrown optional dependency to include version 0.17. #​5973
• Support Python 3.15.0b1. #​6014
• pyo3-ffi is now no_std. #​6022

Added

• Add PyErr::set_traceback to set the traceback of an exception object. #​5349
• Add PyUnicodeDecodeError::new_err_from_utf8 to create a PyErr from a str::Utf8Error. #​5668
• experimental-inspect: implement INPUT_TYPE and OUTPUT_TYPE on optional third-party crate conversions. #​5770
• experimental-inspect: include doc comments in generated stubs. #​5782
• Add pyo3_build_config::PythonAbi, pyo3_build_config::PythonAbiKind, pyo3_build_config::PythonAbiBuilder, pyo3_build_config::InterpreterConfig::target_abi, and pyo3_build_config::InterpreterConfigBuilder::target_abi. #​5807
• Add Borrowed::get as an equivalent to Bound::get and Py::get. #​5849
• Add PyFrame::new, PyTraceBack::new, and PyFrameMethods::line_number. #​5857
• Add PyUntypedBuffer::obj to retrieve the Python object owning the buffer. #​5870
• Add PyCapsule::new_with_value and PyCapsule::new_with_value_and_destructor. #​5881
• Add PyErr::set_context and PyErr::context. #​5887
• Add a small CLI to pyo3-introspection to generate stubs. #​5904
• Add Python::version_str. #​5921
• Add TryFrom<&Bound<T>> for PyRef<T>, PyRefMut<T>, PyClassGuard<T> and PyClassGuardMut<T>. #​5922
• Add From<&Bound<T>> for Bound<T> and Py<T> #​5922
• Add PyDictMethods::set_default and PyDictMethods::set_default_ref to allow atomically setting default values in a PyDict. #​5955
• add PyFrameMethods::outer|code|var|builtins|globals|locals. #​5967
• Add From conversions for PyErr from std::time::TryFromFloatSecsError, std::time::SystemTimeError, std::path::StripPrefixError, std::env::JoinPathsError, std::char::ParseCharError, and std::char::CharTryFromError. #​6001
• Add pyo3_build_config::InterpreterConfigBuilder. #​6034
• Add PyCapsule::import_pointer #​6066
• Add PyClassGuardMapMut. #​6073
• Expose PyListMethods::get_item_unchecked, PyTupleMethods::get_item_unchecked, and PyTupleMethods::get_borrowed_item_unchecked on abi3. #​6075
• Add PyClassGuardMapSuper. #​6104
• Add PyClassGuard and PyClassGuardMut to pyo3::prelude. #​6112
• Add Debug impls for PyClassGuard and PyClassGuardMut. #​6112
• Enable extending PyDateTime, PyDate, PyTime, PyDelta and PyTzInfo on abi3 with python 3.12+. #​6115
• Expose PyFunction available on abi3. #​6117
• FFI definitions:
  • Added FFI definitions PyUnstable_Object_IsUniquelyReferenced, PyUnstable_Object_IsUniquelyReferencedTemporary, PyUnstable_EnableTryIncref, and PyUnstable_TryIncref. #​5828
  • Add FFI definitions ffi::PyErr_GetHandledException and ffi::PyErr_SetHandledException. #​5887
  • Add FFI definition Py_HASH_SIPHASH13. #​5891
  • Add FFI definition PyStructSequence_UnnamedField constant on Python 3.9 and up (or 3.11 with abi3 features). #​5892
  • Add FFI definitions PyUnstable_InterpreterFrame_GetCode, PyUnstable_InterpreterFrame_GetLasti, PyUnstable_InterpreterFrame_GetLine, and PyUnstable_ExecutableKinds. #​5932
  • Add FFI definitions PyMarshal_WriteLongToFile, PyMarshal_WriteObjectToFile, PyMarshal_ReadLongFromFile, PyMarshal_ReadShortFromFile, PyMarshal_ReadObjectFromFile, and PyMarshal_ReadLastObjectFromFile. #​5934
  • Add FFI definitions PyObject_GetAIter, PyAIter_Check, PyMapping_HasKeyWithError, PyMapping_HasKeyStringWithError, PyMapping_GetOptionalItem, PyMapping_GetOptionalItemString, PySequence_ITEM, PySequence_Fast_GET_SIZE, PySequence_Fast_GET_ITEM, and PySequence_Fast_ITEMS. #​5942
  • Add FFI definition compat::PyObject_HasAttrWithError. #​5944
  • Add FFI definitions PyDict_SetDefault, PyDict_SetDefaultRef, PyDict_ContainsString, PyDict_Pop, PyDict_PopString, PyDict_ClearWatcher, PyDict_Watch, PyDict_Unwatch, and PyFrozenDict_New. #​5947
  • Add FFI definitions PyDate_FromDate, PyDateTime_FromDateAndTime, PyDateTime_FromDateAndTimeAndFold, PyTime_FromTime, PyTime_FromTimeAndFold, and PyDelta_FromDSU. #​5949
  • Add FFI definitions PyDict_SetDefaultRef and compat::PyDict_SetDefaultRef. #​5955
    versions.
  • Add FFI definitions for non-limited API header cpython/bytearrayobject.h. #​5966
  • Add FFI definitions for non-limited API version of PyCellObject and associated functions. #​5978
  • Add FFI definition PyErr_WarnExplicitObject. #​5979
  • Add FFI definition PyTracebackObject. #​5980
  • Add FFI definition PyTuple_FromArray on 3.15+. #​5990
  • Add FFI definitions for the PEP 820 PySlot C API. #​6014
  • Add FFI definitions for the critical section API in the limited API on Python 3.15
    and newer. #​6014
  • Add FFI definitions for PEP 757 PyLong import / export API on Python 3.14+. #​6016
  • Add FFI definitions PyEval_SetProfileAllThreads and PyEval_SetTraceAllThreads. #​6038
  • Add FFI definition Py_UNICODE_TODECIMAL. #​6041

Changed

• Change exception enrichment on #[pyfunction] argument extraction error to use PyErr::add_note instead of replacing TypeError instances. #​5349
• Deprecate super-class initialization via tuples. #​5741
• Change module initialization uses the PyModExport and PyABIInfo APIs on Python 3.15+. #​5753
• Deprecate Py<T>::get_refcnt and PyAnyMethods::get_refcnt in favor of pyo3::ffi::Py_REFCNT(obj.as_ptr()). #​5797
• Change PyEnvironmentError, PyIOError, and PyWindowsError to be type aliases of PyOSError (as is the case in Python since 3.3). #​5803
• Change pyo3_build_config::InterpreterConfig::from_interpreter to require an additional stable_abi_version argument. The old behavior is the same as passing None. #​5807
• Change PyList::new to no longer have ExactSizeIterator bound. #​5830
• experimental-inspect: emit #[classattribute] as plain Python class attributes and not functions annotated with @classattribute and @property. #​5839
• experimental-inspect: use object as the input annotation type of magic methods that return NonImplemented if the input value is not of the correct type. #​5841
• Deprecate pyo3-build-config/resolve-config feature. #​5862
• Change pyo3-ffi to use raw-dylib for Windows linking. #​5866
• Deprecate generate-import-lib feature. #​5866
• Allow zero-sized types in PyCapsule::new. #​5889
• PyDate::from_timestamp argument is now a f64 (the Python API expects a float and not an integer) #​5896
• experimental-inspect: Change PathBuf::extract input type hint from str | os.PathLike to str | os.PathLike[str] #​5897
• Remove lifetime from PythonVersionInfo. #​5921
• Remove redundant type checks for methods where CPython guarantees the type of self. #​5930
• Elide temporary reference count cycles inside PyAnyMethods::call, PyAnyMethods::call1 and PyAnyMethods::call_method1 for arguments passed as Rust tuples containing borrowed references to Python objects. #​5941
• Allow type annotations to be used in #[pyo3(signature = ...)] when experimental-inspect feature is not enabled (they will be ignored). #​5999
• pyo3-ffi will now rebuild when the Python virtual environment changes in-place. #​6008
• Change module initialization on 3.15+ to use PEP 820 PySlot API internally. #​6014
• Deprecate direct access to all pyo3_build_config::InterpreterConfig fields; getter methods have been added as replacements. #​6034
• FFI definitions _PyCode_GetExtra, _PyCode_SetExtra, and _PyEval_RequestCodeExtraIndex have been updated to PyUnstable_Code_GetExtra, PyUnstable_Code_SetExtra, and PyUnstable_Eval_RequestCodeExtraIndex. #​6038
• Change PyCapsule::import to return an error if the pointer is not properly aligned. #​6066
• Change PyClassGuardMap to be only for PyClassGuard::map and return PyClassGuardMapMut from PyClassGuardMut::map. #​6073
• Change with_critical_section_mutex2 closure to take Option<EnteredCriticalSection> instead of EnteredCriticalSection as the second argument. #​6098
• PyClassGuardMut::as_super now returns PyClassGuardMutSuper. #​6104
• experimental-inspect: Generate relative imports instead of absolute ones (useful if the stubs are not describing a root package) #​6097

Removed

• Removed the broken (and unfixable) implementations of From<str::Utf8Error>, From<string::FromUtf16Error>, and From<char::DecodeUtf16Error> for PyErr. #​5668
• Remove Py_TRACE_REFS support (unsupported from Python 3.13). #​5824
• experimental-inspect: Remove the TypeInfo enum and the FromPyObject::type_input and IntoPyObject::type_output functions. They are replaced by the PyStaticExpr enum and the FromPyObject::INPUT_TYPE and the IntoPyObject::OUTPUT_TYPE associated constants. #​5893
• Remove all functionality deprecated in PyO3 0.27. #​6068
• FFI definitions:
  • Remove private FFI definitions _PyStack_AsDict, _PyObject_CallNoArg, _PyObject_FastCall, _PyObject_FastCallTstate. _PyObject_VectorcallTstate, _PyObject_MakeTpCall, _Py_CheckFunctionResult, _PyObject_CallFunction_SizeT, _PyObject_CallMethod_SizeT, and _PySequence_IterSearch. #​5942
  • Remove FFI definitions PY_ITERSEARCH_COUNT, PY_ITERSEARCH_INDEX, and PY_ITERSEARCH_CONTAINS. #​5942
  • Removed private FFI definitions _PySet_NextEntry, and _PyLong_NumBits. #​5946
  • Remove private FFI definitions _PyFloat_CAST, _PyRun_SimpleFileObject, _PyRun_AnyFileObject, _PyRun_InteractiveLoopObject, _PyUnicode_CheckConsistency, _PyUnicode_COMPACT_DATA, _PyUnicode_NONCOMPACT_DATA, _PyUnicode_Ready, and _Py_HashBytes. #​6036
  • Remove private FFI definition _PyEval_EvalFrameDefault. #​6038
  • Remove private FFI definition _PyBytes_Resize. #​6042
  • Remove private FFI definitions _PyErr_BadInternalCall, _Py_GetAllocatedBlocks, _PyObject_GC_Malloc, _PyObject_GC_Calloc, and _PyLong_NumBits. #​6053
  • Remove Default for FFI definitions PyHeapTypeObject, PyObjectArenaAllocator, PyHash_FuncDef, and PyType_Spec. #​6093

Fixed

• Fix add_libpython_rpath_link_args emitting rpath link args on wasm targets which don't support rpath. #​5447
• Fix From<string::FromUtf8Error> and From<ffi::IntoStringError> for PyErr producing TypeError due to broken internals. #​5668
• Fix PyMappingProxy::is_type_of and PyWeakrefReference::is_type_of not accepting subclasses. #​5883
• Fix getattr_opt not treating AttributeError subclasses as missing attributes on Python < 3.13. #​5985
• Fix compilation error for #[new] return types that contain named lifetimes. #​5998
• Fix missing 'static bound on PyCapsule destructors. #​6049
• Fix case where PyFrame::builtins could return a non-dict object. #​6052
• Fix type confusion when returning a #[pyclass] from a different pyclass' #[new] method. #​6062
• Fix soundness issue caused by variance in PyClassGuardMap by splitting off the mutable variant. #​6073
• Fix nondeterministic JSON metadata emitted by the experimental-inspect proc macros (to enable reproducible builds). #​6076
• Fix UB in PyEval_RestoreThread when the interpreter is shutting down on Python 3.13 and older (hang the thread instead of allowing pthread_exit to jump across Rust frames). #​6085
• Fix possible out of bounds read in BoundListIterator and BoundTupleIterator's nth and nth_back implementations. #​6086
• Fix BoundListIterator and BoundTupleIterator not being exhausted when nth or nth_back is called with N larger than the remaining count of items. #​6086
• Fix missing Sync bound on closure type in PyCFunction::new_closure. #​6096
• Fix soundness issue caused by exposing a mutable reference from PyClassGuardMut::as_super by moving into PyClassGuardMutSuper. #​6104
• FFI definitions:
  • Fix missing FFI definition for PyTypeObject.tp_versions_used on Python 3.13 and newer. #​5917
  • Mark FFI definitions no longer available on 3.11 and up: PyUnicode_Encode, PyUnicode_EncodeASCII, PyUnicode_EncodeCharmap, PyUnicode_EncodeDecimal, PyUnicode_EncodeLatin1, PyUnicode_EncodeRawUnicodeEscape, PyUnicode_EncodeUTF7, PyUnicode_EncodeUTF8, PyUnicode_EncodeUTF16, PyUnicode_EncodeUTF32, PyUnicode_EncodeUnicodeEscape, PyUnicode_TransformDecimalToASCII, and PyUnicode_TranslateCharmap. #​6041
  • Mark FFI definition PyUnicode_ClearFreeList no longer available on 3.9 and up. #​6041
  • Fix FFI definition PyErr_SetInterruptEx missing c_int return type. #​6043
  • Fix return type of FFI definition PyBuffer_SizeFromFormat on Python 3.8 (was changed from c_int to Py_ssize_t on Python 3.9). #​6090
  • Fix return type of FFI definition PyUnicode_Tailmatch on PyPy (is c_int, unlike CPython). #​6090

v0.28.3

Compare Source

Fixed

• Fix compile error with #[pyclass(get_all)] on a type named Probe. #​5837
• Fix compile error in debug builds related to _Py_NegativeRefcount with Python < 3.12. #​5847
• Fix a race condition where Python::attach or try_attach could return before site.py had finished running. #​5903
• Fix unsoundness in PyBytesWriter::write_vectored with Python 3.15 prerelease versions. #​5907
• Fix deadlock in .into_pyobject() implementation for C-like #[pyclass] enums. #​5928

v0.28.2

Compare Source

Fixed

• Fix complex enum __qualname__ not using python name #​5815
• Fix FFI definition PyType_GetTypeDataSize (was incorrectly named PyObject_GetTypeDataSize). #​5819
• Fix memory corruption when subclassing native types with abi3 feature on Python 3.12+ (newly enabled in PyO3 0.28.0). #​5823

v0.28.1

Compare Source

Fixed

• Fix *args / **kwargs support in experimental-async feature (regressed in 0.28.0). #​5771
• Fix clippy::declare_interior_mutable_const warning inside #[pyclass] generated code on enums. #​5772
• Fix ambiguous_associated_items compilation error when deriving FromPyObject or using #[pyclass(from_py_object)] macro on enums with Error variant. #​5784
• Fix __qualname__ for complex #[pyclass] enum variants to include the enum name. #​5796
• Fix missing std::sync::atomic::Ordering import for targets without atomic64. #​5808

v0.28.0

Compare Source

Packaging

• Bump MSRV to Rust 1.83. #​5531
• Bump minimum supported quote version to 1.0.37. #​5531
• Bump supported GraalPy version to 25.0. #​5542
• Drop memoffset dependency. #​5545
• Support for free-threaded Python is now opt-out rather than opt-in. #​5564
• Bump target-lexicon dependency to 0.13.3. #​5571
• Drop indoc and unindent dependencies. #​5608

Added

• Add __init__ support in #[pymethods]. #​4951
• Expose PySuper on PyPy, GraalPy and ABI3 #​4951
• Add PyString::from_fmt and py_format! macro. #​5199
• Add #[pyclass(new = "from_fields")] option. #​5421
• Add pyo3::buffer::PyUntypedBuffer, a type-erased form of PyBuffer<T>. #​5458
• Add PyBytes::new_with_writer #​5517
• Add PyClass::NAME. #​5579
• Add pyo3_build_config::add_libpython_rpath_link_args. #​5624
• Add PyBackedStr::clone_ref and PyBackedBytes::clone_ref methods. #​5654
• Add PyCapsule::new_with_pointer and PyCapsule::new_with_pointer_and_destructor for creating capsules with raw pointers. #​5689
• Add #[deleter] attribute to implement property deleters in #[methods]. #​5699
• Add IntoPyObject and FromPyObject implementations for uuid::NonNilUuid. #​5707
• Add PyBackedStr::as_str and PyBackedStr::as_py_str methods. #​5723
• Add support for subclassing native types (PyDict, exceptions, ...) when building for abi3 on Python 3.12+. #​5733
• Add support for subclassing PyList when building for Python 3.12+. #​5734
• FFI definitions:
  • Add FFI definitions PyEval_GetFrameBuiltins, PyEval_GetFrameGlobals and PyEval_GetFrameLocals on Python 3.13 and up. #​5590
  • Add FFI definitions PyObject_New, PyObject_NewVar, PyObject_GC_Resize, PyObject_GC_New, and PyObject_GC_NewVar. #​5591
  • Added FFI definitions and an unsafe Rust API wrapping Py_BEGIN_CRITICAL_SECTION_MUTEX and Py_BEGIN_CRITICAL_SECTION_MUTEX2. #​5642
  • Add FFI definition PyDict_GetItemStringRef on Python 3.13 and up. #​5659
  • Add FFI definition PyIter_NextItem on Python 3.14 and up, and compat::PyIter_NextItem for older versions. #​5661
  • Add FFI definitions PyThreadState_GetInterpreter and PyThreadState_GetID on Python 3.9+, PyThreadState_EnterTracing and PyThreadState_LeaveTracing on Python 3.11+, PyThreadState_GetUnchecked on Python 3.13+, and compat::PyThreadState_GetUnchecked. #​5711
  • Add FFI definitions PyImport_ImportModuleAttr and PyImport_ImportModuleAttrString on Python 3.14+. #​5737
  • Add FFI definitions for the PyABIInfo and PyModExport APIs available in Python 3.15. #​5746
• experimental-inspect:
  • Emit base classes. #​5331
  • Emit @typing.final on final classes. #​5552
  • Generate nested classes for complex enums. #​5708
  • Emit async keyword for async functions. #​5731

Changed

• Call sys.unraisablehook instead of PyErr_Print if panicking on null FFI pointer in Bound, Borrowed and Py constructors. #​5496
• Use PEP-489 multi-phase initialization for #[pymodule]. #​5525
• Deprecate implicit by-value implementation of FromPyObject for #[pyclass]. #​5550
• Deprecate PyTypeInfo::NAME and PyTypeInfo::MODULE. #​5579
• Deprecate Py<T>::from_{owned,borrowed}[or_{err,opt}] constructors from raw pointer. #​5585
• Deprecate FFI definitions PyEval_AcquireLock and PyEval_ReleaseLock. #​5590
• Relax 'py: 'a bound in Py::extract. #​5594
• Add a T: PyTypeCheck bound to the IntoPyObject implementations on Bound<T>, Borrowed<T> and Py<T>. #​5640
• The with_critical_section and with_critical_section2 functions are moved to pyo3::sync::critical_section. #​5642
• Use PyIter_NextItem in PyIterator::next implementation. #​5661
• IntoPyObject for simple enums now uses a singleton value, allowing identity (python is) comparisons. #​5665
• Allow any Sequence[int] in FromPyObject on Cow<[u8]> and change the error type to PyErr. #​5667
• async pymethods now borrow self only for the duration of awaiting the future, not the entire method call. #​5684
• Change CastError formatted message to directly describe the "is not an instance of" failure condition. #​5693
• Add #[inline] hints to many methods on PyBackedStr. #​5723
• Remove redundant internal counters from BoundSetIterator and BoundFrozenSetIterator. #​5725
• Implement PyIterator::size_hint on abi3 builds (previously was only on unlimited API builds). #​5727
• Deprecate FFI definition PyImport_ImportModuleNoBlock (deprecated in Python 3.13). #​5737
• #[new] can now return arbitrary Python objects. #​5739
• experimental-inspect:
  • Introduce TypeHint and make use of it to encode type hint annotations. #​5438
  • Rename PyType{Info,Check}::TYPE_INFO into PyType{Info,Check}::TYPE_HINT. #​5438 #​5619 #​5641
  • Fill annotations on function arguments and return values for all types supported natively by PyO3. #​5634 #​5637 #​5639
  • Use _typeshed.Incomplete instead of typing.Any as default type hint, to make it easier to spot incomplete trait implementations. #​5744
  • Use general Python expression syntax for type hints. #​5671

Removed

• Remove all functionality deprecated in PyO3 0.25 and 0.26. #​5740
• FFI definitions:
  • Remove FFI definition PyEval_GetCallStats (removed from CPython in Python 3.7). #​5590
  • Remove FFI definitions PyEval_AcquireLock and PyEval_ReleaseLock on Python 3.13 and up. #​5590
  • Remove private FFI definitions _PyObject_New, _PyObject_NewVar, _PyObject_GC_Resize, _PyObject_GC_New, and _PyObject_GC_NewVar. #​5591
  • Remove private FFI definitions _PyDict_SetItem_KnownHash, _PyDict_Next, _PyDict_NewPresized, _PyDict_Contains_KnownHash, and _PyDict_Contains. #​5659
  • Remove private FFI definitions _PyFrameEvalFunction, _PyInterpreterState_GetEvalFrameFunc and _PyInterpreterState_SetEvalFrameFunc. #​5711
  • Remove private FFI definitions _PyImport_IsInitialized, _PyImport_SetModule, _PyImport_SetModuleString, _PyImport_AcquireLock, _PyImport_ReleaseLock, _PyImport_FindBuiltin, _PyImport_FindExtensionObject, _PyImport_FixupBuiltin, and _PyImport_FixupExtensionObject. #​5737

Fixed

• Fix PyModuleMethods::add_submodule() to use the last segment of the submodule name as the attribute name on the parent module instead of using the full name. #​5375
• Link with libpython for Cygwin extension modules. #​5571
• Link against the limited API DLL for Cygwin when abi3 is used. #​5574
• Handle errors in PyIterator when calling size_hint #​5604
• Link with libpython for iOS extension modules. #​5605
• Correct IntoPyObject output type of PyBackedStr to be PyString, not PyAny. #​5655
• Fix async functions to return None rather than empty tuple (). #​5685
• Fix compile error when using references to #[pyclass] types (e.g. &MyClass) as arguments to async #[pyfunction]s. #​5725
• FFI definitions:
  • Fix FFI definition PyMemberDescrObject.d_member to use PyMemberDef for Python 3.11+ (was incorrectly PyGetSetDef). #​5647
  • Mark FFI definition PyThreadState_GetFrame available with abi3 in 3.10+. #​5711
  • Fix FFI definition PyImport_GetModule on PyPy. #​5737
• experimental-inspect:
  • fix __new__ return type to be the built object type and not None. #​5555
  • fix imports of decorators. #​5618
  • fix the return type annotation of PyResult<()> (must be None and not tuple) #​5674

v0.27.2

Compare Source

Changed

• Disable subclassing PyDict on GraalPy (unsupported for now, may crash at runtime). #​5653

Fixed

• Fix crash when compiling on Rust 1.92+ with both debug assertions and optimizations enabled. #​5638
• Fix FFI definition of PyDictObject on PyPy. #​5653

v0.27.1

Compare Source

Fixed

• Fix clippy:declare_interior_mutable_const warning from #[pyfunction]. #​5538
• Expose pyo3::types::PySendResult in public API. #​5539

v0.27.0

Compare Source

Packaging

• Extend range of supported versions of hashbrown optional dependency to include version 0.16. #​5428
• Bump optional num-bigint dependency minimum version to 0.4.4. #​5471
• Test against Python 3.14 final release. #​5499
• Drop support for PyPy 3.9 and 3.10. #​5516
• Provide a better error message when building an outdated PyO3 for a too-new Python version. #​5519

Added

• Add FromPyObjectOwned as convenient trait bound for FromPyObject when the data is not borrowed from Python. #​4390
• Add Borrowed::extract, same as PyAnyMethods::extract, but does not restrict the lifetime by deref. #​4390
• experimental-inspect: basic support for #[derive(IntoPyObject)] (no struct fields support yet). #​5365
• experimental-inspect: support #[pyo3(get, set)] and #[pyclass(get_all, set_all)]. #​5370
• Add PyTypeCheck::classinfo_object that returns an object that can be used as parameter in isinstance or issubclass. #​5387
• Implement PyTypeInfo on datetime.* types even when the limited API is enabled. #​5388
• Implement PyTypeInfo on PyIterator, PyMapping and PySequence. #​5402
• Implement PyTypeInfo on PyCode when using the stable ABI. #​5403
• Implement PyTypeInfo on PyWeakrefReference when using the stable ABI. #​5404
• Add pyo3::sync::RwLockExt trait, analogous to pyo3::sync::MutexExt for readwrite locks. #​5435
• Add PyString::from_bytes. #​5437
• Implement AsRef<[u8]> for PyBytes. #​5445
• Add CastError and CastIntoError. #​5468
• Add PyCapsuleMethods::pointer_checked and PyCapsuleMethods::is_valid_checked. #​5474
• Add Borrowed::cast, Borrowed::cast_exact and Borrowed::cast_unchecked. #​5475
• Add conversions for jiff::civil::ISOWeekDate. #​5478
• Add conversions for &Cstr, Cstring and Cow<Cstr>. #​5482
• add #[pyclass(skip_from_py_object)] option, to opt-out of the FromPyObject: PyClass + Clone blanket impl. #​5488
• Add PyErr::add_note. #​5489
• Add FromPyObject impl for Cow<Path> & Cow<OsStr>. #​5497
• Add #[pyclass(from_py_object)] pyclass option, to opt-in to the extraction of pyclasses by value (requires Clone). #​5506

Changed

• Rework FromPyObject trait for flexibility and performance: #​4390
  • Add a second lifetime to FromPyObject, to allow borrowing data from Python objects (e.g. &str from Python str).
  • Replace extract_bound with extract, which takes Borrowed<'a, 'py, PyAny>.
• Optimize FromPyObject implementations for Vec<u8> and [u8; N] from bytes and bytearray. #​5244
• Deprecate #[pyfn] attribute. #​5384
• Fetch type name dynamically on cast errors instead of using PyTypeCheck::NAME. #​5387
• Deprecate PyTypeCheck::NAME in favour of PyTypeCheck::classinfo_object which provides the type information at runtime. #​5387
• PyClassGuard(Mut) and PyRef(Mut) extraction now returns an opaque Rust error #​5413
• Fetch type name dynamically when exporting types implementing PyTypeInfo with #[pymodule_use]. #​5414
• Improve Debug representation of PyBuffer<T>. #​5442
• experimental-inspect: change the way introspection data is emitted in the binaries to avoid a pointer indirection and simplify parsing. #​5450
• Optimize Py<T>::drop for the case when attached to the Python interpreter. #​5454
• Replace DowncastError and DowncastIntoError with CastError and CastIntoError. #​5468
• Enable fast-path for 128-bit integer conversions on GraalPy. #​5471
• Deprecate PyAnyMethods::downcast functions in favour of Bound::cast functions. #​5472
• Make PyTypeCheck an unsafe trait. #​5473
• Deprecate unchecked PyCapsuleMethods: pointer(), reference(), and is_valid(). #​5474
• Reduce lifetime of return value in PyCapsuleMethods::reference. #​5474
• PyCapsuleMethods::name now returns CapsuleName wrapper instead of &CStr. #​5474
• Deprecate import_exception_bound in favour of import_exception. #​5480
• PyList::get_item_unchecked, PyTuple::get_item_unchecked, and PyTuple::get_borrowed_item_unchecked no longer check for null values at the provided index. #​5494
• Allow converting naive datetime into chrono DateTime<Local>. #​5507

Removed

• Removed FromPyObjectBound trait. #​4390

Fixed

• Fix compilation failure on wasm32-wasip2. #​5368
• Fix OsStr conversion for non-utf8 strings on Windows. #​5444
• Fix issue with cargo vendor caused by gitignored build artifact emscripten/pybuilddir.txt. #​5456
• Stop leaking PyMethodDef instances inside #[pyfunction] macro generated code. #​5459
• Don't export definition of FFI struct PyObjectObFlagsAndRefcnt on 32-bit Python 3.14 (doesn't exist). #​5499
• Fix failure to build for abi3 interpreters on Windows using maturin's built-in sysconfig in combination with the generate-import-lib feature. #​5503
• Fix FFI definitions PyModule_ExecDef and PyModule_FromDefAndSpec2 on PyPy. #​5529

v0.26.0

Compare Source

Packaging

• Bump hashbrown dependency to 0.15. #​5152
• Update MSRV to 1.74. #​5171
• Set the same maximum supported version for alternative interpreters as for CPython. #​5192
• Add optional bytes dependency to add conversions for bytes::Bytes. #​5252
• Publish new crate pyo3-introspection to pair with the experimental-inspect feature. #​5300
• The PYO3_BUILD_EXTENSION_MODULE now causes the same effect as the extension-module feature. Eventually we expect maturin and setuptools-rust to set this environment variable automatically. Users with their own build systems will need to do the same. #​5343

Added

• Add #[pyo3(warn(message = "...", category = ...))] attribute for automatic warnings generation for #[pyfunction] and #[pymethods]. #​4364
• Add PyMutex, available on Python 3.13 and newer. #​4523
• Add FFI definition PyMutex_IsLocked, available on Python 3.14 and newer. #​4523
• Add PyString::from_encoded_object. #​5017
• experimental-inspect: add basic input type annotations. #​5089
• Add FFI function definitions for PyFrameObject from CPython 3.13. #​5154
• experimental-inspect: tag modules created using #[pymodule] or #[pymodule_init] functions as incomplete. #​5207
• experimental-inspect: add basic return type support. #​5208
• Add PyCode::compile and PyCodeMethods::run to create and execute code objects. #​5217
• Add PyOnceLock type for thread-safe single-initialization. #​5223
• Add PyClassGuard(Mut) pyclass holders. In the future they will replace PyRef(Mut). #​5233
• experimental-inspect: allow annotations in #[pyo3(signature)] signature attribute. #​5241
• Implement MutexExt for parking_lot's/lock_api ReentrantMutex. #​5258
• experimental-inspect: support class associated constants. #​5272
• Add Bound::cast family of functions superseding the PyAnyMethods::downcast family. #​5289
• Add FFI definitions Py_Version and Py_IsFinalizing. #​5317
• experimental-inspect: add output type annotation for #[pyclass]. #​5320
• experimental-inspect: support #[pyclass(eq, eq_int, ord, hash, str)]. #​5338
• experimental-inspect: add basic support for #[derive(FromPyObject)] (no struct fields support yet). #​5339
• Add Python::try_attach. #​5342

Changed

• Use Py_TPFLAGS_DISALLOW_INSTANTIATION instead of a __new__ which always fails for a #[pyclass] without a #[new] on Python 3.10 and up. #​4568
• PyModule::from_code now defaults file_name to <string> if empty. #​4777
• Deprecate PyString::from_object in favour of PyString::from_encoded_object. #​5017
• When building with abi3 for a Python version newer than pyo3 supports, automatically fall back to an abi3 build for the latest supported version. #​5144
• Change is_instance_of trait bound from PyTypeInfo to PyTypeCheck. #​5146
• Many PyO3 proc macros now report multiple errors instead of only the first one. #​5159
• Change MutexExt return type to be an associated type. #​5201
• Use PyCallArgs for Py::call and friends so they're equivalent to their Bound counterpart. #​5206
• Rename Python::with_gil to Python::attach. #​5209
• Rename Python::allow_threads to Python::detach #​5221
• Deprecate GILOnceCell type in favour of PyOnceLock. #​5223
• Rename pyo3::prepare_freethreaded_python to Python::initialize. #​5247
• Convert PyMemoryError into/from io::ErrorKind::OutOfMemory. #​5256
• Deprecate GILProtected. #​5285
• Move #[pyclass] docstring formatting from import time to compile time. #​5286
• Python::attach will now panic if the Python interpreter is in the process of shutting down. #​5317
• Add fast-path to PyTypeInfo::type_object for #[pyclass] types. #​5324
• Deprecate PyObject type alias for Py<PyAny>. #​5325
• Rename Python::with_gil_unchecked to Python::attach_unchecked. #​5340
• Rename Python::assume_gil_acquired to Python::assume_attached. #​5354

Removed

• Remove FFI definition of internals of PyFrameObject. #​5154
• Remove Eq and PartialEq implementations on PyGetSetDef FFI definition. #​5196
• Remove private FFI definitions _Py_IsCoreInitialized and _Py_InitializeMain. #​5317

Fixed

• Use critical section in PyByteArray::to_vec on freethreaded build to replicate GIL-enabled "soundness". #​4742
• Fix precision loss when converting bigdecimal into Python. #​5198
• Don't treat win7 target as a cross-compilation. #​5210
• WASM targets no longer require exception handling support for Python < 3.14. #​5239
• Fix segfault when dropping PyBuffer<T> after the Python interpreter has been finalized. #​5242
• experimental-inspect: better automated imports generation. #​5251
• experimental-inspect: fix introspection of __richcmp__, __concat__, __repeat__, __inplace_concat__ and __inplace_repeat__. #​5273
• fixed a leaked borrow, when converting a mutable sub class into a frozen base class using PyRef::into_super #​5281
• Fix FFI definition Py_Exit (never returns, was () return value, now !). #​5317
• experimental-inspect: fix handling of module members gated behind #[cfg(...)] attributes. #​5318