Mine works on Catalina with SIP on. Qt and PyQt is always an issue, however you can build from source without Qt if you just want a base ROS2 Setup for communication and dev work. I built most of my multi-agent RL frameworks using just a base install without Qt. I was able to get RQt working after an update by Qt for macOS.
The following is a method of installing without needing Qt from a twitter thread I made.
When you download the ROS2 Foxy files using vcs, cd into the src folder and you should see this when you list everything (ls):
Next, add COLCON_IGNORE files to these two directories to enable our minimal install of ROS2. The first is ros-visualization/ and the second is: ros2/rviz
To add the COLCON_IGNORE file, change directory to the first of these directories and run the command touch COLCON_IGNORE as shown below.
When you list what’s in the directory (ls) that file should pop up.
Now change directory back to your src folder with cd .. and go to the ros2/rviz folder using cd to add the COLCON_IGNORE folder as shown below.
I have used the ls command to show the before and after of adding the file.
That’s it! You have enabled a minimal install of ROS2 by forcing colcon to ignore (thus the name “COLCON_IGNORE”) when compiling your ROS2 install. Change directory back to your workspace (ros2_foxy) with the cd ../../.. command and continue with the rest of the ROS2 installation guide.