This should fix the issues with libfmt. If you compile from source and then clean package depending on open3d_catkin (e.g. open3d_slam_ros) and then try to build it again you get linking errors. This fix should resolve it. To reproduce the error:
remove any open3d install
catkin clean
catkin build open3d_slam_ros (this should build from source and it should work)
catkin clean open3d_slam_ros
catkin build open3d_slam_ros (this should complain about libfmt)
This should fix the issues with libfmt. If you compile from source and then clean package depending on open3d_catkin (e.g. open3d_slam_ros) and then try to build it again you get linking errors. This fix should resolve it. To reproduce the error: