ModuleNotFoundError: No module named 'dmp'

[RayYoh]

When I use Ubuntu18.04, Python 3.8, and I run the examples plot_cart_pole.py, I get an error ModuleNotFoundError: No module named 'dmp'.
But when I use Python2.7, everything goes well. And I find a file named 'demo.so', but there is nothing when I use Python3.8

[maotto]

I could not reproduce this error with a python3.8 conda environment on Ubuntu 18.04. I get DeprecationWarnings, but the example still runs fine. While the conda environment has no dmp module, running the cart pole example in my case doesn't lead to importing dmp.
Can you post your error with traceback please?

These are the commands I used for the test:

conda create --name bolerotest380 python=3.8
conda activate bolerotest380
sudo apt install cython3
export PYTHON=python3
wget https://raw.githubusercontent.com/rock-learning/bolero/master/bootstrap_bolero.sh
chmod +x bootstrap_bolero.sh
./bootstrap_bolero.sh
cd bolero-dev
source env.sh
pip install pyyaml distro matplotlib scipy sklearn gym
python learning/bolero/examples/behavior_search/plot_cart_pole.py