🐛 Describe the bug

https://pytorch.org/docs/stable/objects.inv (and searchindex.js, .buildinfo) return 404 since pytorch/docs#84 was merged 2026-04-29 23:09 UTC. This breaks intersphinx for every downstream Sphinx project that cross-references PyTorch, and breaks mkdocstrings-based docs (mkdocs build --strict aborts).

Symptom

Sphinx:

WARNING: failed to reach any of the inventories with the following issues:
intersphinx inventory 'https://pytorch.org/docs/stable/objects.inv' not fetchable due to <class 'urllib.error.HTTPError'>: HTTP Error 404: Not Found

mkdocstrings (--strict):

ERROR - mkdocstrings: Couldn't load inventory https://pytorch.org/docs/stable/objects.inv through handler 'python': HTTP Error 404: Not Found
Aborted with 1 errors, 20 warnings in strict mode!

Root cause

pytorch/docs#84 replaced filesystem symlinks under stable/, master/, 1.7.0/, 1.9.0/ with per-page HTML redirect stubs, generated by scripts/make_stubs.py --mirror-canonical. The script has

DEFAULT_KEEP = {"searchindex.js", "objects.inv", ".buildinfo"}

with intent to preserve those files as real bytes under each alias, and the default walk-alias mode honors it correctly. The bug: --mirror-canonical mode iterates iter_canonical_html() (filtered to .html), so keep-listed files are never copied. The PR's "Caveat" section flagged that interactive deep-links to _static/_images would 404, but didn't surface that objects.inv is in the same bucket — and that one is the machine-readable contract surface for every Sphinx project in the ecosystem.

Blast radius

Workarounds shipped (all pin to /docs/<X.Y>/):

• vllm-project/vllm#41353
• isaac-sim/IsaacLab#5452 (merged)
• newton-physics/newton#2660 (merged)

Latently broken (intersphinx pytorch.org/docs/stable/ but no docs CI run since the merge):

• Lightning-AI/pytorch-lightning (both pytorch and fabric confs)
• pytorch/vision
• pytorch/audio
• pytorch/text
• skorch-dev/skorch

Unaffected:

• HuggingFace stack (transformers/accelerate/diffusers/peft) uses HF's own doc-builder, not Sphinx + intersphinx.
• pyg-team/pytorch_geometric pre-pinned to /docs/main/.

Fix

Surgical patch to scripts/make_stubs.py: pytorch/docs#85. Adds ~13 MB to the deploy artifact (still 99.5% of #84's savings, far under the 10 GB Pages cap).

Versions

Affects production docs at pytorch.org/docs/stable (and master, 1.7.0, 1.9.0) since 2026-04-29 23:09 UTC.

cc @svekars @sekyondaMeta @AlannaBurke