Some jobs might benefit of knowing in which workflow they are being run (e.g. nightly build or regular CI). Right now it's possible to get this information by making an API call to
and take it from there, but it would make it a lot easier if it's available as an environment variable (e.g. CIRCLE_WORKFLOW_NAME).
(I also found this feature request https://discuss.circleci.com/t/expose-workflow-name-as-environment-variable/19470 on the same topic)