sphinx-build module not found in sbuild

[Jérémy Lal]

Hi,

I'm stuck at this odd behavior:

when I build a package in my current environment (debian/testing),
sphinx-build ... works correctly.

when building in sbuild, sphinx-build doesn't find current module:
ModuleNotFoundError: No module named 'xxx'
in docs/conf.py at
from xxx import __version__

I don't understand which other debian package is modifying that outcome.

Any idea ?