Lens Pre Pr Check

Pre-PR gate

Everything CI will check, run locally first, plus the conventions CI cannot check but reviewers will. Work top to bottom; stop and fix rather than collecting a list.

State the real result of each step. A skipped or failing step reported as passing is worse than no check at all.

1. Know what you are shipping

git status --short
git log --oneline main..HEAD
git diff main...HEAD --stat

Confirm the diff is only what the change is about. Stray edits to uv.lock, generated pages under docs/fern/product-docs/, .env, or a compose file you toggled while testing should come out now.

2. Lint and format

ruff check src tests --fix
ruff format src tests

Then run what CI's lint job actually runs, which is the pre-commit hooks over the whole tree:

pre-commit run --all-files

If pre-commit modified files, stage them and re-run until clean.

3. Tests

pytest -q

The full suite is fast; run all of it rather than a subset. If anything fails, fix it — do not rationalize a pre-existing failure without first checking whether it also fails on main.

For a change with meaningful coverage implications:

pytest --cov=nemo.lens --cov-report=term-missing

Codecov comments on PRs and compares against the base commit. semconv.py is excluded by config; every other new line should be exercised.

4. Copyright headers

New Python modules and new .github/workflows/*.yml files need the SPDX + Apache-2.0 header; a copyright-check workflow runs on every PR. Other config YAML — compose files, observability/* — carries none, so match the directory you are adding to rather than applying the header blindly. List new files and confirm:

git diff main...HEAD --name-only --diff-filter=A
head -3 <each new file>

Copy the header verbatim from a neighbouring file in the same directory — the year and wording must match what CI expects.

5. Docs

If the change is user-visible — a new or renamed env var, span group, metric, public symbol, or any behavior change a user could notice — the matching page under docs/ needs updating. AGENTS.md's routing table says which page.

Then:

• A new page must be registered in docs/fern/versions/nightly.yml, or it will build fine and simply never appear in the sidebar.
• Doc edits belong in docs/ (nightly). Changes landing under docs/fern/versions/0.1.0/pages/ are a backport to a frozen release — make sure that is deliberate.
• MDX requires self-closing <img ... />; CI hard-fails on a bare <img>.
• CI runs an offline link check over docs/**/*.mdx, so relative links must resolve on disk. A link to a .md file that is actually .mdx will fail.

If Node is available and docs changed:

npm --prefix docs/fern run check

6. Commits

git log main..HEAD --format='%H%n%an <%ae>%n%(trailers:key=Signed-off-by)%n---'

Every commit needs a Signed-off-by trailer matching the commit author — DCO is enforced and a single unsigned commit blocks the PR. Fix with git rebase --signoff main (or git commit --amend -s for a single commit).

Commit messages are ordinary; the strict convention is on the PR title.

7. PR title and body

• Title must follow Conventional Commits. A CI check rejects anything else. Allowed types: feat, fix, chore, docs, style, refactor, test, ci, build, perf, revert. Mark a breaking change with ! or a BREAKING CHANGE: trailer.
• Do not open as a draft. The CI workflow carries an explicit fail-on-draft guard. This is the opposite of the Megatron-LM convention.
• Fill in the PR template's checkboxes honestly, including the cross-repo _fallbacks.py box. Ticking it means the PR description names which consumer files need the matching edit — Megatron-LM/megatron/core/telemetry/, RL/nemo_rl/telemetry/, Gym/nemo_gym/telemetry/ — and what the new signature is. None of those repos are in this checkout and their CI does not run against your branch, so an unticked or hand-waved box is how consumers find out from a bug report.

CI runs against a pull-request/NNN mirror branch created by NVIDIA's copy-pr-bot rather than against your branch directly, so allow for the mirror step before expecting checks to appear.

8. Final read

Re-read your own diff once, as a reviewer would. Look for debugging leftovers, commented-out code, a TODO you meant to resolve, and — specific to this repo — an opentelemetry.sdk import that wandered outside providers.py.

git diff main...HEAD
grep -rn "opentelemetry\.sdk" src/ | grep -v providers.py

For a substantial change, apply skills/lens-review/SKILL.md to the diff before pushing. In Claude Code, delegate it to the lens-reviewer subagent.

Report

Summarize: what passed, what you fixed, what still fails and why, and anything you consciously skipped. Then state whether the branch is ready to push.