When trying to run a model on pyactr with Python 3.10:

python package 'pyactr' not found. Please ensure it is installed with pip or is in your PYTHONPATH env variable

The problem here is that pyactr is using a deprecated import for collections.Sequence in chunks.py (& possibly elsewhere?). What was a deprecation warning in Python <= 3.9 is now an error in 3.10.

See: Stack Overflow question