Changelog

To be included in v0.5.2- (if present)

v0.5.2- [UNRELEASED DRAFT]

(2026-06-24)

Removals and backward incompatible breaking changes

  • Dropped support for free-threaded Python 3.13 – by @Vizonex.

    Related issues and pull requests on GitHub: #223.

Packaging updates and notes for downstreams

  • The setuptools build dependency lower bound has been restored to be >= 47 after an incorrect automated increase in PR #207 – by @bbhtt.

    Related issues and pull requests on GitHub: #207.

  • Dropped support for free-threaded Python 3.13 – by @Vizonex.

    Related issues and pull requests on GitHub: #223.

Contributor-facing changes

  • Dependabot has been restricted to the requirements subdirectory to avoid unintended updates outside dependency requirement files – by @bbhtt.

    Related issues and pull requests on GitHub: #207.

  • Added an AGENTS.md file with contributor guidance for AI coding agents, adapted from the yarl equivalent – by @bdraco.

    Related issues and pull requests on GitHub: #231.

  • Migrated from standalone black and isort pre-commit hooks to ruff format and the ruff I lint rule, sharing a new [tool.ruff] config in pyproject.toml. ruff-check runs with --fix so import-order fixes apply on commit, and the orphan [isort] block in setup.cfg was removed – by @bdraco.

    Related issues and pull requests on GitHub: #232.

  • Switched the cibuildwheel build frontend to build[uv] so that uv provisions every build and test virtual environment in the wheel matrix. Test-dependency installation in particular drops from a multi-second pip install per ABI to a roughly sub-second uv resolve – by @bdraco.

    Related issues and pull requests on GitHub: #234.

  • Dropped the libffi-devel install from the cibuildwheel Linux before-all step. It was added in PR #75 so cffi could build from source during wheel testing; the current wheel-test chain no longer pulls in cffi, so the header package is dead weight – by @bdraco.

    Related issues and pull requests on GitHub: #236.

  • The type preciseness coverage report generated by MyPy is now uploaded to Coveralls and will not be included in the Codecov views going forward – by @aiolibsbot.

    Related issues and pull requests on GitHub: #239.

  • Switched CI/CD to tox-dev/workflow’s reusable-tox.yml driven by an in-tree tox.ini. The build, metadata-validation and lint (pre-commit, spellcheck-docs) jobs all run through the reusable workflow; mypy coverage uploads to Coveralls from a post-tox-job hook – by @bdraco.

    Related issues and pull requests on GitHub: #243.

  • Overrode CIBW_BUILD_FRONTEND=build for the QEMU-emulated odd-arch wheel matrix, since the pypa odd-arch container images do not ship uv preinstalled and the project’s pyproject.toml sets build-frontend = "build[uv]" – by @bdraco.

    Related issues and pull requests on GitHub: #246.

  • Allowed re-running the deploy job after a partial release failure: the Make Release step now skips when the GitHub Release already exists, and the PyPI publish step uses skip-existing so dists that were already uploaded on a prior attempt do not break the retry – by @bdraco.

    Related issues and pull requests on GitHub: #247.

  • Switched the aarch64 and armv7l wheel builds to GitHub’s native ARM runners. The aarch64 wheels now build without QEMU emulation, and armv7l runs on aarch64 hosts so its 32-bit ARM execution is far cheaper than the previous aarch64-on-x86_64 path – by @bdraco.

    Related issues and pull requests on GitHub: #248.

  • Added UV_CONSTRAINT and UV_BUILD_CONSTRAINT alongside PIP_CONSTRAINT and PIP_BUILD_CONSTRAINT in the cibuildwheel environment so the requirements/cython.txt pin is honored under the build[uv] frontend; uv pip ignores the PIP_ variables and reads only the UV_ ones, while the PIP_ variants are kept for the pip fallback path – by @bdraco.

    Related issues and pull requests on GitHub: #249.

  • Fixed coverage for testing benchmarks when codspeed is not installed – by @Vizonex.

    Related issues and pull requests on GitHub: #251.

Released versions

0.5.2

(2026-05-08)

No significant changes.

0.5.1

(2026-05-08)

No significant changes.

0.5.0

(2026-05-08)

Features

  • Added support for newer type hints and remove Optional and Union from all annotations – by @Vizonex

    Related issues and pull requests on GitHub: #193.

Removals and backward incompatible breaking changes

  • Dropped support for Python 3.9 as it has reached end of life.

    Related issues and pull requests on GitHub: #216.

Packaging updates and notes for downstreams

  • Changed the Cython build dependency from ~= 3.1.0 to >= 3.2.0, removing the upper version bound to avoid conflicts for downstream packagers – by @jameshilliard and @gundalow.

    The upstream Cython version is pinned to 3.2.4 in the CI/CD environment.

    Related issues and pull requests on GitHub: #184, #188, #214.

  • Start building and shipping riscv64 wheels – by @justeph.

    Related issues and pull requests on GitHub: #194.

  • The PEP 517 build backend now supports a new build-inplace config setting (and PROPCACHE_BUILD_INPLACE environment variable) for controlling whether to build the project in-tree or in a temporary directory. It only affects wheels and is set up to build in a temporary directory by default. It does not affect editable wheel builds; they will keep being built in-tree regardless.

    Here’s an example of using this setting:

    $ python -m build --config-setting=build-inplace=true

    Additionally, when building wheels in an automatically created temporary directory, the build backend now normalizes the respective file system path to a deterministic source checkout directory by injecting the -ffile-prefix-map compiler option into the CFLAGS environment variable, as suggested by known reproducible build practices.

    The effect is that downstreams will get reproducible build results.

    Related issues and pull requests on GitHub: #218.

0.4.1

(2025-10-08)

Bug fixes

  • Fixed reference leak caused by Py_INCREF because Cython has its own reference counter systems – by @Vizonex.

    Related issues and pull requests on GitHub: #162.

Contributor-facing changes

  • Fixes the default value for the os parameter in reusable-build-wheel.yml to be ubuntu-latest instead of ubuntu.

    Related issues and pull requests on GitHub: #155.

0.4.0

(2025-10-04)

Features

  • Optimized propcache by replacing sentinel object for checking if the object is NULL and changed dict API for Python C-API – by @Vizonex.

    Related issues and pull requests on GitHub: #121.

Contributor-facing changes

  • Builds have been added for arm64 Windows wheels and the reusable-build-wheel.yml workflow has been modified to allow for an OS value (windows-11-arm) which does not include the -latest postfix – by @finnagin.

    Related issues and pull requests on GitHub: #133.

  • Added CI for CPython 3.14 – by @kumaraditya303.

    Related issues and pull requests on GitHub: #140.

0.3.2

(2025-06-09)

Improved documentation

Packaging updates and notes for downstreams

  • Updated to use Cython 3.1 universally across the build path – by @lysnikolaou.

    Related issues and pull requests on GitHub: #117.

  • Made Cython line tracing opt-in via the with-cython-tracing build config setting – by @bdraco.

    Previously, line tracing was enabled by default in pyproject.toml, which caused build issues for some users and made wheels nearly twice as slow.

    Now line tracing is only enabled when explicitly requested via pip install . --config-setting=with-cython-tracing=true or by setting the PROPCACHE_CYTHON_TRACING environment variable.

    Related issues and pull requests on GitHub: #118.

0.3.1

(2025-03-25)

Bug fixes

  • Improved typing annotations, fixing some type errors under correct usage and improving typing robustness generally – by @Dreamsorcerer.

    Related issues and pull requests on GitHub: #103.

0.3.0

(2025-02-20)

Features

  • Implemented support for the free-threaded build of CPython 3.13 – by @lysnikolaou.

    Related issues and pull requests on GitHub: #84.

Packaging updates and notes for downstreams

  • Started building wheels for the free-threaded build of CPython 3.13 – by @lysnikolaou.

    Related issues and pull requests on GitHub: #84.

Contributor-facing changes

  • GitHub Actions CI/CD is now configured to manage caching pip-ecosystem dependencies using re-actors/cache-python-deps – an action by @webknjaz that takes into account ABI stability and the exact version of Python runtime.

    Related issues and pull requests on GitHub: #93.

0.2.1

(2024-12-01)

Bug fixes

Removals and backward incompatible breaking changes

  • Removed support for Python 3.8 as it has reached end of life – by @bdraco.

    Related issues and pull requests on GitHub: #57.

Packaging updates and notes for downstreams

  • Stopped implicitly allowing the use of Cython pre-release versions when building the distribution package – by @ajsanchezsanz and @markgreene74.

    Related commits on GitHub: 64df0a6.

0.2.0

(2024-10-07)

Bug fixes

  • Fixed loading the C-extensions on Python 3.8 – by @bdraco.

    Related issues and pull requests on GitHub: #26.

Features

Improved documentation

Packaging updates and notes for downstreams

0.1.0

(2024-10-03)

Features

  • Added armv7l wheels – by @bdraco.

    Related issues and pull requests on GitHub: #5.

0.0.0

(2024-10-02)

  • Initial release.