[x] changes made to print more information about arviz import error for debugging purpose
example of updated error msg (now the second line about scipy error shows):
E ImportError: The arviz package is required for this functionality. Please make sure arviz is installed. See below for the original error message:
E cannot import name 'gaussian' from 'scipy.signal' (/opt/hostedtoolcache/Python/3.9.19/x64/lib/python3.9/site-packages/scipy/signal/__init__.py)
cuqi/samples/_samples.py:24: ImportError
There is a recent issue with arviz import.
example of updated error msg (now the second line about scipy error shows):