add documentation for pydefix in virtualenv

[glesur]

No description provided.

[neutrinoceros]

This has much more consequences and can easily create a worse situation for a user, especially if they see the export as a suggestion to hardcode this line into a .bashrc or similar config file.
I'd strongly advise against this.

[glesur]

I don't see where it says this should be in .bashrc. My question would be: do you have a better proposition?

[neutrinoceros]

to be more constructive, I would suggest making pydefix a proper Python package if it makes sense (and it doesn't, there is a bigger problem to address here)

[neutrinoceros]

I don't see where it says this should be in .bashrc.

I'm just saying this is typically where export statements from documentation / modifications to PYTHONPATH end up, and it's never¹ the right solution.

Footnotes

1. from the limited scope of my own experience ↩

[glesur]

the problem is not due to pydefix (a c++ class in idefix), but to pybind11, which is already a python package. On Idefix startup, pybind11 does not necessarily pick up the python interpreter from the current venv.

[neutrinoceros]

I think I need to study how this is implemented for a couple minutes (possibly longer) before I can meaningfully contribute to this discussion, but I strongly feel like I should. Can I get back to you later this week ?

[glesur]

for future reference:
the proposed fix comes from:
https://stackoverflow.com/questions/53480120/embedding-pybind11-with-virtual-environment

Similar issues may be found on the web, such as:
https://gitlab.kitware.com/autopybind11/autopybind11/-/issues/97