1. install ros like normal http://wiki.ros.org/noetic/Installation/Ubuntu
2. create a python virtual env
3. virtualenv venv --system-site-packages
4. install my code-specific python dependencies
5. use wstool to populate my catkin workspace from the .rosinstall file
apt install python3-rosdep python3-catkin-tools python3-osrf-pycommon python3-wstool
catkin build -c
This may have errors, ignore them for now. Just source the devel/setup.bash
sudo rosdep init
rosdep update
use rosdep to install dependencies, rosdep install -a -r, do not add -y because it might install something you don't want, like python2
now build and hopefully no errors
catkin build