Can't import RPN libraries in non-activated env.

https://github.com/sebastiendfortier/conda_packaging/blob/6c2d21e04b90d34b39a284c48a6ca653fae32c02/conda_recipies/python-rpn/conda.recipe/etc/conda/activate.d/env_vars.sh#L1

I fully understand why you would use the activate hooks to set that variable, but this breaks a few setups that I think are more common than one would think:

Using jupyter lab installed in one env and starting the rpn kernel from another env.
Executing code through an IDE (PyCharm, VSCode)
Executing code through a conda env inside docker/apptainer

In all of these cases, the conda environment that contains librmn and others is not actually activated before being used. Therefore, importing the python packages fails with something similar to :

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/exec/pbourg/.conda/eccc/lib/python3.11/site-packages/fstpy/__init__.py", line 9, in <module>
    import rpnpy.librmn.all as rmn
  File "/exec/pbourg/.conda/eccc/lib/python3.11/site-packages/eccc_rpnpy-2.2.0rc3-py3.11.egg/rpnpy/librmn/__init__.py", line 115, in <module>
  File "/exec/pbourg/.conda/eccc/lib/python3.11/site-packages/eccc_rpnpy-2.2.0rc3-py3.11.egg/rpnpy/librmn/__init__.py", line 104, in loadRMNlib
OSError: [Errno -1] Failed to find librmn.so: : 'librmn.so'

I had the same problem with ESMF and it was fixed by making a guess about the library location if the env variable was not set. See : https://github.com/esmf-org/esmf/pull/151

The error could be fixed by adding os.path.join(sys.prefix, 'lib') to the list of paths in https://github.com/sebastiendfortier/python-rpn/blob/a72c862d37c28e9b9a67e7c8aa590c292808397e/lib/rpnpy/librmn/__init__.py#L93-L101

Does that make sense ? I could suggest a PR in the other repo, but I suspect github isn't the main.

(PS: Tu me le dis si tu préfères les courriels, ou le français)

sebastiendfortier / conda_packaging

Can't import RPN libraries in non-activated env. #1