New submission from Antoine Pitrou <pitrou@free.fr>: In the doc for `-X` options (https://docs.python.org/3/using/cmdline.html#id5), when an option can be triggered through an equivalent environment variable, that variable is mentioned. An exception to that is `-X dev`, which can also be triggered by the PYTHONDEVMODE variable, but that isn't mentioned in the CLI doc. Other missing environment variables in the CLI doc are PYTHONFAULTHANDLER and PYTHONTRACEMALLOC. ---------- assignee: docs@python components: Documentation keywords: easy, newcomer friendly messages: 362414 nosy: docs@python, eric.araujo, ezio.melotti, mdk, pitrou, vstinner, willingc priority: normal severity: normal stage: needs patch status: open title: Doc for `-X dev` option should mention PYTHONDEVMODE type: enhancement versions: Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue39712> _______________________________________