This manifested in this pr: ros2/rviz#243

Basically, the urdf from somewhere like /usr/include (not sure exactly where from) when they should have been found in the workspace where rviz was being built.

Catkin had a way to deal with this by sorting include directories by workspace folder order, placing all include paths outside of any of the workspaces last in the order. ament_cmake should provide a function to emulate this behavior in order to better support overlaying.

@mikaelarguedas or @dirk-thomas feel free to add more details if you have them.

Also, this new function should either be used everywhere or at least where it has been a problem before, and in either case the pr linked above should be fixed with this function as well.