https://python-devtools.helpmanual.io/usage/#usage-without-import

Suggests the following snippet:

    __builtins__['debug'] = debug

In python 3.10 (at least, only version tried), referencing builtins directly gives "TypeError: 'module' object is not subscriptable"

builtins.dict, however, is subscriptable.

That figuring out where sitecustomize.py (or usercustomize.py) actually can be put so it gets properly executed on startup on a multi-python and/or brew (linuxbrew) system is an absolute nightmare is a different issue and not one I'd expect python-devtools to address particularly.