Hi,
I’m new to ROS and ROS2. It took me also a few days and I left attempts to compile, switching to the binary release of Eloquent:
https://index.ros.org/doc/ros2/Installation/Eloquent/macOS-Install-Binary/
after fixing a lot of broken symbol links like:
Library not loaded: /usr/local/opt/poco/lib/libPocoFoundation.63.dylib
solving using:
ln -s /usr/local/opt/poco/lib/libPocoFoundation.71.dylib /usr/local/opt/poco/lib/libPocoFoundation.63.dylib
I was able to begin to go over tutorials up to colcon requiring ability to compile things.
Hope it helps.