ModuleNotFoundError: No module named 'ruamel'

I am trying to run pymatgen on under Jupyter on my Mac (MacOS 11.6.1) with conda. I made a new (as of today) installation of miniconda and ran “conda update conda” without problem. I then made an environment for pymatgen using “conda env -n pymatgen” without problem. I install pymatgen from anaconda "conda install -c conda-forge pymatgen " as well as Jupyter “conda install Jupyter”. All seems well, but when I try doing loading some pymatgen libraries “from pymatgen.core.structure import Structure, Lattice” I encounter the error “ModuleNotFoundError: No module named ‘ruamel’”. runamel seems to be installed and installing it via conda’s pip doesn’t resolve the problem either. There are some references to this being a namespace problem that conda has a hard time dealing with. Is there a simple solution to fixing this?

The detailed error message is below

ModuleNotFoundError Traceback (most recent call last)
----> 1 from pymatgen.core.structure import Structure, Lattice
2 from pymatgen.core.periodic_table import Element

~/.local/lib/python3.7/site-packages/pymatgen/ in
13 import os
14 import warnings
—> 15 import ruamel as yaml
16 from fnmatch import fnmatch

ModuleNotFoundError: No module named ‘ruamel’