GeezerVison

PyO3 0.30.1 is a re-release of PyO3 0.30.0 after investments in CI security unfortunately led to a failed crates.io publish. Rather than delete the failed tag, this new tag comes after the CI issues have (hopefully) been corrected.

Thanks to @davidhewitt @Tpt and @Viicos for the investigation and fixes.

Contributors

This release brings confirmed testing against Python 3.15.0 final. Support for Python 3.8 has been dropped. The minimum supported Rust version has also been increased to 1.85.

The largest sets of improvements come to PyO3 0.29.0's experimental-inspect feature, which has received substantial feedback since 0.29.0 and subsequently has seen many refinements to improve the quality and coverage to the generated stubs. Thank you to everyone who has helped to continue to drive this feature towards completion.

New safe wrappers for PyFrozenDict (3.15+) and PyContext have been added.

PyO3 now contains meson build files, which should make it possible for projects using meson-python to more straightforwardly use Rust and PyO3 for additional components.

Additionally, a number of small optimizations have landed, including:

• simplifications to core implementations of PyAnyMethods,
• reduced overhead from PyO3's internal "reference pool" used to dispose of Py<T> values dropped when not attached to the interpreter,
• optimizations to num-bigint conversions, and
• better generated code from IntoPyObject and IntoPyObjectRef derives.

There are also many other incremental improvements, bug fixes and smaller features; full detail can be found in the CHANGELOG.

Please consult the migration guide for help upgrading.

Thank you to everyone who contributed code, documentation, design ideas, bug reports, and feedback. The following contributors' commits are included in this release:

@adamgerhant-ai
@alex
@bschoenmaeckers
@charliermarsh
@chirizxc
@clin1234
@davidhewitt
@dependabot[bot]
@dylanpulver
@elbaro
@exg
@florentinl
@FranciscoTGouveia
@Icxolu
@imfeh2
@IvanIsCoding
@JMak-Security
@jonasdedden
@jorenham
@konstin
@latent-9
@MatthieuDartiailh
@mattip
@mejrs
@msimacek
@musicinmybrain
@ngoldbaum
@overcat
@Person-93
@PeterFaiman
@ratazzi
@rewitt94
@scott-griffiths
@ShaharNaveh
@ShiroKSH
@sneakers-the-rat
@tobni
@Tpt
@vasiliy-poverennov-dd
@WaterWhisperer
@xavierforge

Contributors

This release is a series of fixes worth landing to the PyO3 0.29 series; the PyO3 0.30 release is planned to follow within a few weeks, however during the development cycle a number of rough edges were discovered which were deemed worth a backport.

The patch broadly includes:

• a further fix the to the opt-out of raw-dylib linking for Windows introduced in PyO3 0.29.1 (the switch to raw-dylib linking was introduced in PyO3 0.29.0),
• fixes to support GraalPy on windows,
• a handful of small performance optimizations,
• a number of non-breaking fixes to the experimental-inspect type stub generation (expect more improvements in 0.30), and
• various other bugfixes such as to FFI definitions, to resolve crashes, and to fix clippy lints caused by PyO3 macros.

For a full list of the exact fixes please consult the CHANGELOG.

Thank you to the following contributors for the improvements:

@adamgerhant-ai
@alex
@bschoenmaeckers
@charliermarsh
@chirizxc
@davidhewitt
@dependabot[bot]
@dylanpulver
@exg
@FranciscoTGouveia
@JMak-Security
@jonasdedden
@jorenham
@konstin
@latent-9
@mejrs
@ngoldbaum
@Person-93
@PeterFaiman
@sneakers-the-rat

Contributors

This patch fixes a regression in PyO3 0.29.1 which broke PyPy 3.11 compatibility (#[pyclass] types would crash PyPy on instance deletion).

A few further fixes have also landed with similar themes to PyO3 0.29.1: fixes to minor reference counting bugs, rough edges which would cause crashes, issues which would cause failed builds, and fixes to experimental-inspect type stub generation.

For a full list of the exact fixes please consult the CHANGELOG.

Thank you to the following contributors for the improvements:

@davidhewitt
@dependabot[bot]
@imfeh2
@musicinmybrain
@Tpt
@WaterWhisperer

Contributors

This patch is a stack of fixes for PyO3 0.29. Particular themes include:

• Fixes addressing build failures with newer interpreters such as GraalPy 3.13 and CPython 3.15
• Fixes resolving potential memory leaks inside #[pyclass] implementation internals
• Fixes to the new experimental-inspect type stub machinery

For a full list of the fixes in these above themes and more, please consult the CHANGELOG.

Thank you to the following contributors for the improvements:

@alex
@bschoenmaeckers
@chirizxc
@davidhewitt
@dependabot[bot]
@exg
@imfeh2
@IvanIsCoding
@jonasdedden
@MatthieuDartiailh
@msimacek
@ngoldbaum
@Person-93
@ratazzi
@rewitt94
@scott-griffiths
@ShiroKSH
@tobni
@Tpt
@WaterWhisperer

Contributors

This release is a relatively large release with improvements across many areas of PyO3's API.

Build and packaging changes

This release brings full support for Python 3.15 beta. We encourage downstream projects to begin testing and distributing Python 3.15 beta wheels so that the ecosystem can prepare for the 3.15 final release later in the year.

Alongside Python 3.15 support comes support for its new "abi3t" stable ABI which supports both free-threaded and gil-enabled Python builds. For projects distributing stable ABI wheels, we recommend distributing (for each OS/architecture) an abi3 wheel built for your minimum supported Python version, a 3.14t version-specific wheel for free-threaded Python 3.14, and an abi3t wheel to support Python 3.15 (and future versions).

Support for Python 3.7 has been dropped. Support for Python 3.13t, the first experimental free-threaded release of CPython, has also been dropped. 3.14t (and soon 3.15t) is more stable, performant, and the starting point for CPython's own declaration of "support" for the free-threaded build.

The PyO3 build process (via the pyo3-build-config crate) has been adjusted to reduce the cost of rebuilds when the environment used to detect the Python interpreter changes; pyo3-build-config and pyo3-macros will no longer be rebuilt in such cases (although pyo3-ffi and crates downstream of it still will be rebuilt). As a consequence the pyo3_build_config APIs now require crates to have a direct dependency on pyo3 or pyo3-ffi. We hope to continue to reduce rebuild frequency and cost in a future PyO3 release.

Security updates

With the recent boom in AI-assisted security scanning, PyO3 has inevitably had several correctness issues exposed by AI-assisted scanning.

In particular, PyO3 0.29 fixes two security vulnerabilities we will be releasing to the RustSec Advisory Database imminently:

• Missing Sync bound on PyCFunction::new_closure closures
• Possible out of bounds read in BoundTupleIterator::nth_back and BoundListIterator::nth_back

Any code using the above APIs is advised to update as soon as possible.

This release also contains several other minor breaking changes to close soundness holes uncovered by AI-assisted scanning. Our assessment as maintainers was that, excluding the two vulnerability cases listed above, these correctness issues would likely have crashed immediately upon user testing rather than leading to attacker-exploitable pathways. We nevertheless wanted to see them closed without the usual deprecation cycle. These cases are noted in the migration guide.

Other major themes in this release

New in this release is a CLI in pyo3-introspection to generate type stubs along with the experimental-inspect feature. Downstream, maturin has also gained support to generate type stubs using the feature. The feature is reaching a point where substantial amount of type stubs can be generated automatically. We would like to encourage users to begin using this feature and helping us find what functionality is missing, with a hope we can declare its API stable given sufficient feedback.

A substantial amount of effort has been invested in pyo3-ffi as part of the process of extending it with 3.15's new APIs. There have been many missing APIs from older Python versions added. There have also been a number of fixes to incorrect definitions (these are breaking changes, but also necessary for correctness); we hope there will be far fewer such cases in the future due to more comprehensive checking added to PyO3's CI. Finally, many private CPython APIs (those with _Py underscore-named prefix) have been removed from pyo3-ffi's public API.

In closing

There are also many other incremental improvements, bug fixes and smaller features; full detail can be found in the CHANGELOG.

Please consult the migration guide for help upgrading.

Thank you to everyone who contributed code, documentation, design ideas, bug reports, and feedback. The following contributors' commits are included in this release:

@Alc-Alc
@alex
@anuraaga
@BD103
@bschoenmaeckers
@Cheukting
@chirizxc
@ChristopherRabotin
@clin1234
@codeguru42
@davidhewitt
@dependabot[bot]
@Embers-of-the-Fire
@funsafemath
@Harikeshav-R
@hoodmane
@Icxolu
@IntrepidT
@jelmer
@luxedo
@MatthieuDartiailh
@maurosilber
@mejrs
@messense
@ngoldbaum
@Person-93
@quyentonndbs
@rara64
@staticintlucas
@tbates-redarc
@tdyas
@Tpt
@winstxnhdw

Contributors

This patch contains several fixes for stability of the PyO3 0.28.x series:

• Python::attach and Python::try_attach will no longer return before the thread initializing the interpreter has finished runnning site.py when using the auto-initialize feature.
• Fix unsoundness in PyBytesWriter::write_vectored when targeting the Python 3.15 prerelease interpreter.
• Fix possible deadlock in .into_pyobject() implementation for C-like #[pyclass] enums.

A couple of edge cases causing compile failures were also fixed.

Thank you to the following contributors for the improvements:

@alex
@bschoenmaeckers
@chirizxc
@davidhewitt
@Embers-of-the-Fire
@Icxolu
@maurosilber
@ngoldbaum

Contributors

This patch release contains a soundness fix for subclassing native types such as PyList with the abi3 feature enabled when targeting a minimum version of Python 3.12 or higher. (Support for doing such subclassing was newly added in PyO3 0.28.0.)

PyO3 0.28.0 and 0.28.1 will be yanked.

This release also contains a correction to the FFI definition PyType_GetTypeDataSize and incorrectly-generated __qualname__ on #[pyclass] enum variant types when using #[pyo3(name = "...")] option to rename the enum and/or variant.

Thank you to the following contributors for the improvements:

@davidhewitt
@Icxolu
@ngoldbaum

Contributors

This patch contains a number of minor compile-time fixes for PyO3 0.28.0.

Thank you to the following contributors for the improvements:

@davidhewitt
@funsafemath
@ngoldbaum
@rara64
@tdyas

Contributors

This release contains many improvements across PyO3's feature set:

• Proper support for __init__ methods for #[pyclass] types
• Support for #[deleter]s to complement the existing #[getter] and #[setter] attributes when implementing class "properties".
• Support for subclassing many Python types with the abi3 feature (requires Python 3.12+).
• A new #[pyclass(new = "from_fields")] option to automatically define the constructor from the class fields.
• Many corrections to FFI definitions (including removal of many private CPython methods)
• Many improvements to the experimental-inspect feature's functionality.

The minimum supported Rust version has been increased to Rust 1.83.

This release also switches #[pymodule] to use PEP 489 multi-phase initialization internally. This should have no immediate functional impact other than preparing PyO3 to support newer technologies such as Python subinterpreters.

There are also many other incremental improvements, bug fixes and smaller features; full detail can be found in the CHANGELOG.

Please consult the migration guide for help upgrading.

Thank you to everyone who contributed code, documentation, design ideas, bug reports, and feedback. The following contributors' commits are included in this release:

@ABorgna
@ahlinc
@alex
@altendky
@bazaah
@bschoenmaeckers
@chirizxc
@clin1234
@davidhewitt
@dependabot[bot]
@freakboy3742
@henryp3278
@Icxolu
@lazka
@LilyFirefly
@linkmauve
@lmmx
@lukaslueg
@MatthieuDartiailh
@MusicalNinjaDad
@ngoldbaum
@pkalivas
@reaperhulk
@RedKinda
@SilasMarvin
@SoroushMoosapour
@stijndcl
@tpoliaw
@Tpt

Contributors