When I running Multi-TB3 simulation with use_composition:=True (default), Nav2 stack does not start:

[leha@leha-PC nav2_ws]$ ros2 node list
/gazebo
/launch_ros_4468
/robot1/intel_realsense_r200_depth_driver
/robot1/nav2_container
/robot1/robot_state_publisher
/robot1/rviz
/robot1/transform_listener_impl_7fe25c0109c0
/robot1/turtlebot3_diff_drive
/robot1/turtlebot3_imu
/robot1/turtlebot3_joint_state
/robot1/turtlebot3_laserscan
/robot2/intel_realsense_r200_depth_driver
/robot2/nav2_container
/robot2/robot_state_publisher
/robot2/rviz
/robot2/transform_listener_impl_7fc7e4001800
/robot2/turtlebot3_diff_drive
/robot2/turtlebot3_imu
/robot2/turtlebot3_joint_state
/robot2/turtlebot3_laserscan

When disabling it, everything works fine.

Bug report

Required Info:

• Operating System:
  • Ubuntu 20.04
• ROS2 Version:
  • ROS2 Rolling built from sources
• Version or commit hash:
  • 42d0bbd
• DDS implementation:
  • CycloneDDS

Steps to reproduce issue

ros2 launch nav2_bringup multi_tb3_simulation_launch.py autostart:=True

Expected behavior

Nav2 stack starts

Actual behavior

Nav2 main nodes do not start

Additional information

It turns out, that running tb3_simulation_launch.py with some non-empty root namespace works only with disabled composition nodes. If enable use_composition parameter for that case, no nodes from localization_launch.py and navigation_launch.py (map_server, amcl, controller, smoother, etc...) are starting. This appears without any error or warning messages in the console: fail.log