Ros2 topic echo /scan --once and --filed not working

There seems some problem with the ros2 topic echo. please see the attached screenshot. I was working in rosject. Note that
“ros2 topic echo /scan” works perfectly fine. but if i use --once, --field it doesn’t work.

Hi,

I believe this is because the rosject you are working on has a distribution where --once is not implemented yet.

To check, you can do what the ouptut suggests and do ros2 topic -h to check available options.

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Hi,
Thanks for your reply. I want to request the developing team to please implement/update the rosject to the latest version of ros2. Presently, I believe the rosject is using foxy which is old and doesnt support these flags.

Thanks again for your reply and would appreciate if you are linked to the developers then it would be very helpful if you can take this issue forward.