Installation issues v5.9 macOS

Not sure I get your question. I installed on a Macbook Pro M2, thus Silicon architecture and I got the error. I also installed on a x86 linux machine and everything was fine there.

In both cases, I created a fresh conda environment with the command

conda create -c conda-forge -n pymc_env "pymc>=5"

as per the official documentation on the pymc website.