Build was crashing inside torchaudio's setup.py with:
ModuleNotFoundError: No module named 'torch'
PIP_CONSTRAINT was correctly pinning torch/torchvision in the install
target env, but pip's PEP 517 build isolation creates a SEPARATE fresh
Python env just for the build wheel step — and that env has no torch
in it. torchaudio's setup.py imports torch to discover CUDA flags, so
it crashes. Pip even printed a deprecation warning that this isolation
behavior is hardening, not relaxing.
Fix:
1. Pre-install torchaudio's build deps (setuptools, wheel, ninja,
pybind11) into the main env since we're disabling isolation.
2. Add --no-build-isolation to the torchaudio install so the build
uses NGC's torch directly.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Keysat
a24610ad2a