I had similar problems. The following worked for me a couple of months ago. Installations are into fresh environments.
INSTALL RELEASE 3.11.2
conda create --name pymc3.11.2 python=3.9
conda activate pymc3.11.2
conda install -c conda-forge mkl pymc3 theano-pymc
pip3 install jupyter
INSTALL FROM LOCAL REPOSITORY
conda create -n pydev2 python=3.9.5
conda activate pydev2
pip install -e .
pip install Jupyter
python -m ipykernel install --user --name pydev2 --display-name “pydev2”
INSTALL PYTEST:
python3.9 -m pip install pytest