“ARNING: no messages received and simulated time is active”解决办法

I am running 2 nodes. One is polar_scan_matcher and the other one is my own node that publishes scan messages. Something is wrong somewhere because when the 2 nodes run at the same time, the publisher of the scan messages is being block as I received an error saying "WARNING: no messages received and simulated time is active. Is /clock being published?" when I run "rostopic echo -c /scan"

It looks like you've somehow set the "use_sim_time" parameter to true, but you don't have a clock source (ie: rosbag play --clock or some other source, like Gazebo).

Since you're using tf, WallTime isn't an option.

You can check the status of the use_sim_time parameter by using rosparam.

rosparam get use_sim_time

And if it is set somehow, you can reverse it by running:

rosparam set use_sim_time false