Extend notebook_validator.py with a colab-diff subcommand that
fetches three files from googlecolab/backend-info:
pip-freeze.gpu.txt -> snapshot at scripts/data/colab_pip_freeze.gpu.txt
apt-list-gpu.txt -> snapshot at scripts/data/colab_apt_list.gpu.txt
os-info-gpu.txt -> snapshot at scripts/data/colab_os_info.gpu.txt
Each file is parsed with a format-specific parser (pip ==, apt
listing, free-form os-info) and compared against the committed
snapshot. The diff reports NEW / REMOVED / CHANGED keys per file.
Wired into Notebooks CI two ways:
- PR-time static job: advisory step (continue-on-error: true) so
upstream Colab rotations surface in the PR check UI without
blocking authors.
- Daily static-with-pypi cron: --strict step so backend-info drift
fails the cron within ~24h and the maintainer can refresh the
snapshots intentionally.
Catches the same bug classes the existing R-INST-002/003/004/005
rules catch, but earlier: when Colab bumps libcudnn / Python /
torch wheels, we hear about it before a notebook breaks.
Add baseline snapshots from current backend-info HEAD: 1136 apt
packages, 4 os-info entries, 720 pip-freeze entries.