feat: create free-threaded python wheels#1553
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The free-threaded matrix entries skip `uv sync` to avoid resolving project dependencies against cp313t/cp314t (many dev deps lack free-threaded wheels), so `uv run --no-project maturin` failed on macOS/Windows with "Failed to spawn: `maturin`". Switch to `uvx maturin@1.8.1`, which runs maturin in an isolated tool env independent of the project venv and matches the pin used by maturin-action for manylinux builds. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
maturin's `--interpreter python3.14t` fails on Windows because the free-threaded build ships as plain `python.exe` (no `tN` suffix). Look up `sys.executable` of the python on PATH (which actions/setup-python prepends with the free-threaded install), assert `Py_GIL_DISABLED == 1` so a misconfigured PATH can't silently build a GIL wheel, and normalize backslashes to forward slashes so the path survives re-expansion in the downstream `run:` line. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Windows free-threaded Python does not expose `abiflags` in sysconfig, so PyO3's default Windows linkage path fails with "A python 3 interpreter on Windows does not define abiflags in its sysconfig ಠ_ಠ" when building cp31Xt wheels. Enabling the `generate-import-lib` PyO3 feature switches Windows builds to a generated import library (provided by the `python3-dll-a` crate) that does not depend on a fully populated sysconfig. It is a no-op on macOS and Linux and is compatible with the existing `abi3` feature. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
maturin 1.8.1 errors out on Windows free-threaded interpreters with "A python 3 interpreter on Windows does not define abiflags in its sysconfig" even when given a valid `python.exe`. Newer maturin releases handle the missing abiflags gracefully for cp31Xt builds. Bump both the `uvx maturin@` pin used for native macOS/Windows wheels and the `maturin-version` passed to PyO3/maturin-action for the manylinux containers. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The mac/Windows matrix shared a single name template that prepended "macOS arm64 & Windows" to every entry, which got truncated in the GitHub UI sidebar and made it hard to tell macOS and Windows runs apart. Rename all wheel build jobs to the same pattern so the OS, architecture, and python tag are visible at a glance: - Linux x86_64 / arm64 - macOS arm64 / x86_64 - Windows x86_64 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
pygithub pulls in cryptography via pyjwt[crypto]. cryptography 44.0.0 ships only abi3 wheels, which free-threaded interpreters cannot use, so uv builds it from sdist; its bundled PyO3 0.23.2 caps at Python 3.13 and fails on 3.14t. pygithub is only used by the manual release changelog script, so move it out of the dev group into a new release group. 'uv sync --dev' (used by CI test jobs) no longer drags in cryptography.
Passing a bare version like '3.13t' to 'uv venv --python' let uv fall back to a different system interpreter (3.12), creating a venv whose ABI did not match the downloaded cp313t wheel and failing the install. Use the python-path output from setup-python so the venv uses exactly the interpreter that was set up.
Pinning only 'uv venv --python' was not enough: 'uv sync' ignores the existing .venv, runs its own interpreter discovery, and recreated the venv with the system 3.12, again mismatching the cp313t wheel. Set UV_PYTHON to the setup-python interpreter for the install and test steps so every uv command (venv, sync, pip, run) uses it.
Setting UV_PYTHON on the test step pointed 'uv run --no-project pytest' at the setup-python interpreter, which has no pytest installed, causing 'Failed to spawn: pytest'. UV_PYTHON is only needed in the install step to build the .venv with the right interpreter; the test step must use that .venv. Drop UV_PYTHON from the test step. Co-Authored-By: Claude <noreply@anthropic.com>
Setting UV_PYTHON as a step env split the install across two environments: 'uv sync' populated .venv while 'uv pip install' targeted the bare setup-python interpreter, so the datafusion wheel never landed in .venv and 'import datafusion' failed under pytest. Pin the interpreter at 'uv venv --python', activate the venv, and pass --active to 'uv sync' so sync and pip install both target the same .venv. Co-Authored-By: Claude <noreply@anthropic.com>
Activating the venv and passing --active still let 'uv sync' run its own interpreter discovery, which skips free-threaded builds and re-picked the system 3.12, recreating .venv and breaking the cp313t/cp314t wheel install. Pass the venv's own interpreter (.venv/bin/python) explicitly to 'uv sync', 'uv pip install', and 'uv run' so every step stays in the free-threaded environment created by 'uv venv'. Co-Authored-By: Claude <noreply@anthropic.com>
ntjohnson1
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May 27, 2026
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Build stuff all tracks and the frozen wrapper classes should help ensure most things are stable by design. Otherwise I haven't done a deep dive into concerns around exposing bindings to free threading. Any thoughts on concerns around race conditions etc / additional tests that might be worth having for free threading?
I guess if we release the wheels we'll start getting community feedback if we have issues.
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Which issue does this PR close?
Closes #1324
Rationale for this change
Starting in Python 3.14 free-threaded support is no longer experimental.
What changes are included in this PR?
Update build to support free-threaded Python wheels.
Are there any user-facing changes?
None