PEP668 / pipx and "--editable" installs

[c.buhtz at posteo.jp]

On 2023-09-18 10:16 "Peter J. Holzer via Python-list"
<python-list at python.org> wrote:
> On 2023-09-15 14:15:23 +0000, c.buhtz--- via Python-list wrote:
> > I tried to install it via "pipx install -e .[develop]". It's
> > pyproject.toml has a bug: A missing dependency "dateutil". But
> > "dateutil" is not available from PyPi for Python 3.11 (the default
> > in Debian 12). But thanks to great Debian they have a
> > "python3-dateutil" package. I installed it.
> 
> This can be installed via pip:

I'm aware of this. But this is not the question.

I would like to know and understand why my via "pipx" installed package
"hyperorg" is not able to see the systems packages installed via "apt
install python3-dateutils"?

Is this the usual behavior? Is this correct?
What is the design decision behind it?

Is it really the intention of PEP668 that pipx-installed packages are
not allowed to use system packages?