Bridging same topic via multiple nodes leads to a conflict

[k12onoss]

Environment

• OS Version: Ubuntu 24.04
• Source or binary build? binary

Description

So, I ran into this issue while working with multi-robot simulation. I am using the cloned_multi_tb3_simulation_launch.py from the nav2 package, which launches a separate bridge for each instance of the tb3 robot that you spawn. As a result, the /clock topic is bridged multiple times. This leads to the following issues:

• Detected jump back in time. Clearing TF buffer.
• Message Filter dropping message: frame 'base_scan' at time 7.600 for reason 'the timestamp on the message is earlier than all the data in the transform cache'

• Expected behavior:
  There's no mismatch in the messages published.
• Actual behavior:
  Leads to some conflict. I've verified this by essentially omitting the /clock topic from being bridged for each robot instance and instead have a separate bridge for it.

Steps to reproduce

1. Launch the cloned_multi_tb3_simulation_launch.py file.

[azeey]

I'm not sure what the fix should be here. It seems to me the right thing to do is to only bridge global topics like /clock only once.

[azeey]

I'm going to close this issue since it seems like a configuration problem. I think the fix is to make sure the /clock topic is briged once in your project or, in this case, in nav2_bringup.