Agent skill · NVIDIA
mcore-testing
Test system for Megatron-LM. Covers test layout, recipe YAML structure, adding and running unit and functional tests, golden values, marker filters, and CI parity.
What it needs
About 4k tokens when loaded.
What this skill does
Testing Guide --- Answer-First Testing Facts For questions about disabling tests without deleting them: Functional recipe entries stay in YAML; disable by suffixing scope with -broken, for example scope: [mr-github] -> scope: [mr-github-broken]. Unit-test skips use pytest markers instead: @pytest.mark.flakyindev skips in the default dev environment, and @pytest.mark.flaky skips in LTS. Do not delete the test case or recipe entry when the goal is discoverability and easy re-enable. --- Test Layout --- How Tests Execute The GitHub Actions runner invokes launchnemorunworkload.py, which uses nemo-run to launch a DockerExecutor container. The repo is bind-mounted at /opt/megatron-lm; training data is mounted at /mnt/artifacts. Unit tests are dispatched through torch.distributed.run: Ranks 0 and 3 are tee-d to stdout; all other ranks write only to log files. Per-rank log files land at {assetsdir}/logs/1/ and are uploaded as a GitHub artifact after the run. Functional tests are driven by tests/functionaltests/shelltestutils/runcitest.sh. Only rank 0 runs the pytest validation step; training output from all ranks is uploaded as an artifact. Flaky-failure auto-retry: launchnemorunworkload.py retries up to 3 times for known transient patterns (NCCL timeout, ECC error, segfault, HuggingFace connectivity, …) before declaring a genuine failure. --- Recipe YAML Structure Recipes live in tests/testutils/recipes/ and are parsed by tests/testutils/pythonscripts/recipeparser.py. Each file expands a cartesian products block into individual workload specs: Key runtime placeholders: {assetsdir}, {artifactsdir}, {testcase}, {environment}, {platforms}, {nrepeat}. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills NVIDIA/mcore-testing