Drop support for the free-threaded build of CPython 3.13#776
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cibuildwheel 3.4.1 deprecated the cpython-freethreading enable flag and treats 3.13t as experimental. Drop 3.13t from the test matrix and remove the enable flag from pyproject.toml so wheels stop being produced for 3.13t. 3.14t remains in place. Refs: https://cibuildwheel.pypa.io/en/stable/changelog/#v341 Refs: aio-libs/yarl#1667
bdraco
approved these changes
May 19, 2026
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What do these changes do?
Drop the experimental free-threaded build of CPython 3.13 from
the test matrix and stop emitting
cp313twheels. cibuildwheel3.4.1 deprecated the
cpython-freethreadingenable flag and isremoving it in the next release; 3.13t is no longer recommended
for production use. 3.14t support stays in place (it is enabled
by default in cibuildwheel and remains in the test matrix).
See https://cibuildwheel.pypa.io/en/stable/changelog/#v341 and
the matching yarl change at aio-libs/yarl#1667.
Are there changes in behavior for the user?
The next release of frozenlist will not include
cp313twheels.Users on the free-threaded build of CPython 3.13 will need to
install from sdist (and have a C/C++ toolchain available) or
upgrade to CPython 3.14t.
Related issue number
Fixes #775
Checklist
CONTRIBUTORS.txtCHANGESfolderAgent run details (optional, for reviewers)
Drafted with Kōan running Claude Opus 4.7; pending human review before being marked ready.
Changes:
.github/workflows/ci-cd.yml: removed3.13tfrom thepyvermatrix.pyproject.toml: removedenable = ["cpython-freethreading"]from[tool.cibuildwheel].CHANGES/775.breaking.rst: news fragment.Verified by inspecting the cibuildwheel changelog and the yarl PR (aio-libs/yarl#1667) referenced in the issue; no behavioural code was touched, so the test suite was not re-run for this change.
Quality Report
Changes: 4 files changed, 3 insertions(+), 2 deletions(-)
Code scan: clean
Tests: failed (FAILED)
Branch hygiene: clean
Generated by Kōan post-mission quality pipeline