[JarryShaw]

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#1958 phase 4. Stacked on #2006, so it lands after that one. GraalPy stays experimental, and this does not close #1958.

• Tier: 3.14t becomes supported. load() accepts a supported free-threaded build only when its default build is also supported. builds() keeps 3.14t out of pypi, conda and engine-tests, because the cp314 wheel is pure Python and installs on 3.14t.
• Legs: 3.14t moves from experimental.yml into test and integration and gains Compat Python 3.14t. The ruleset must add that context.
• GIL off: the 3.14t legs set PYTHON_GIL=0 and uninstall lxml. lxml 6 declares no Py_mod_gil, and its maintainer reports crashes without the GIL (LP#2111289).
• GIL guards: tests/_gil_guard.py and a conftest hook fail the first teardown that finds the GIL on, on a free-threaded build under Actions. The Compat leg fails if import pcapkit turns the GIL on.
• Weekly job: it keeps hand-kept lines whatever their tier.
• Tests: new tests/project/test_free_threaded_supported_1958.py. The existing tier and prose pins are updated, and the unit-tests.yml citations are re-derived.

[JarryShaw]

GOOD TO GO at ebb556642, reviewed as its own commit on top of #2006.

A Sonnet cross-review confirmed:

• Empty PYTHON_GIL on other legs is harmless. CPython's _Py_GetEnv ignores an empty value, while PYTHON_GIL=0 on a non-free-threaded 3.14 refuses to start. So the empty-string fallback is the right one.
• lxml. Its free-threading support only arrives in 7.0.0a1 ("Experimental"); stable is 6.1.3. Nothing in the 3.14t tiers needs lxml: the vendor parsers use html5lib and the tests gate on HAS_LXML.
• The GIL guard runs in every xdist worker. The Compat verify step exits 0 on non-free-threaded builds.
• Matrices. util/python_versions.py --github-output puts 3.14t in test, integration and compatibility, and leaves it out of pypi, conda, pypi-wheels and engine-supported.
• Ruleset 23497679. It lists Required checks passed plus Compat Python 3.11 to 3.15, so Compat Python 3.14t is the only context to add. required-checks already needs test and integration.
• Tests. The selected pins give 246 passed.

I'll add Compat Python 3.14t to the ruleset once this merges; adding it earlier would block every other PR on a check only this one reports. The new Integration Python 3.14t leg runs for the first time here and is worth watching.

[github-actions]

Coverage: 91.54% (unit tier, Python 3.15, e2d2af916, Unit Tests run success)

Package	Statements	Missed	Branches	Partial	Cover
pcapkit (top level)	104	4	20	2	95.16%
pcapkit/const	19597	881	2618	867	92.11%
pcapkit/corekit	2567	71	816	37	96.57%
pcapkit/dumpkit	282	3	102	3	98.44%
pcapkit/foundation	2930	23	1022	25	98.79%
pcapkit/interface	138	4	52	3	96.32%
pcapkit/protocols	17436	219	4582	185	98.15%
pcapkit/toolkit	872	36	298	10	95.21%
pcapkit/utilities	529	7	160	5	98.26%
pcapkit/vendor	4431	1995	1018	167	51.73%

Per-file detail: the coverage-html artifact of this run.

[JarryShaw]

GOOD TO GO at e2d2af916.

The 3.15 failure in test_conda_platform_pin_refresh_1851 was caused by this PR, and the fix is a real one.

• Cause: util/conda_vendor.py's conda_pythons() read the whole supported tier, so it now included 3.14t. --refresh-pins then wanted a cp314t wheel for a conda build that doesn't exist, and left the pin where it was.
• Fix: it now uses builds(), the same list as the conda output, which excludes free-threaded builds.

A Sonnet re-review of the delta confirmed:

• the change is only conda_vendor.py plus a new test;
• conda_pythons() returns 3.11–3.15 with no 3.14t;
• nothing else reads the supported tier in a way that 3.14t breaks;
• the new test fails on ebb556642;
• the related files give 99 passed.

That the pin stayed put while the run exited 0 is a separate, pre-existing gap, filed on its own.

[JarryShaw]

Ordering check, since the "Plain unittest ordering" job is skipped on PRs. I ran every leg of it, sequentially and with CI's own command, on main 185b3176f + #2024 (which contains this PR's two commits).

• OK: cli (235), const (584), dumpkit (285), foundation (699), interface (258), protocols/internet (712), protocols (rest) (1393), toolkit (425), utilities (370) and vendor (388).
• project: failed once on ci: promote free-threaded 3.14t to supported, with the GIL off (#1958) #2024's old head, in ci: promote free-threaded 3.14t to supported, with the GIL off (#1958) #2024's own conda pin test. On ci: promote free-threaded 3.14t to supported, with the GIL off (#1958) #2024's fixed head e2d2af916 it gives 1698, OK.

The KTLO legs report 0 failing test ids across 15 legs.

[JarryShaw]

#2006 landed as 609bd9370, so I rebased this onto it as 8695757e2, keeping only the 3.14t commit. The tree is byte-identical to e2d2af916, so the earlier verdict and ordering run still hold. Out of draft. It will conflict with #2023 in python-compatibility.yml and workflows.rst once either lands; I'll rebase the second one.

[JarryShaw]

Closing per the 02:05Z ruling on #1967: 3.14t stays experimental, and lxml may turn the GIL on there. That removes every part of this PR: the promotion, the GIL guard, the lxml uninstall, Compat Python 3.14t and the ruleset change. The conda_vendor fix mattered only with 3.14t supported. #2025 is unblocked. The branch stays if this comes back.