ros2 runtime_error ai_generated true

ros2 bag play: Clock time is not being published

ID: ros2/ros2-bag-play-clock-error

Also available as: JSON · Markdown

90%Fix Rate

88%Confidence

3Evidence

2023-01-01First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
2	active	—	—	—

Nodes use use_sim_time:=true but ros2 bag play is not publishing /clock, or vice versa.

generic

95% success Use --clock flag when playing bags

ros2 bag play my_bag --clock 100  # publishes /clock at 100 Hz

90% success Set use_sim_time:=true on ALL nodes when replaying bags
```
ros2 launch my_pkg replay.launch.py use_sim_time:=true
```
85% success Use --rate to control playback speed while keeping clock consistent
```
ros2 bag play my_bag --clock 100 --rate 0.5  # half speed
```

Common approaches that don't work:

Set use_sim_time on some nodes but not others 90% fail
Causes TF extrapolation errors: some nodes use wall clock, others use sim time
Publish /clock manually at a fixed rate 82% fail
Clock must advance with bag time, not independently; manual clock causes data-time mismatch