uorb top not showing uORB message, even though it is streaming

[js-motocrane]

Describe the bug
I followed the steps in the PX4 documentation to create a custom uORB message and publish it, within my custom application. I went to the nsh shell in QGroundControl to try and confirm my message was streaming by typing uorb top , however when I did this, I did not see my custom uORB topic anywhere in the list (I thoroughly searched through it). Based on a suggestion from the PX4 Slack message I posted, I tried uorb top my_uorb and it displayed the topic there correctly.

Worth noting is that once I got this uORB message to feed a custom MAVLink message, it is displayed in the uorb top list. However, when this is not happening (and when there are no other subscribers to that uORB topic), the uORB message is not displayed in the list.

To Reproduce
Steps to reproduce the behavior:

1. Create new uORB message, advertise and publish it from a running application/module
2. Use the uorb top command in the nsh shell (from QGC)

Expected behavior
The custom uORB message should be there in the list of topics.

Log Files and Screenshots
Sorry, I did not capture any screenshots, but I hope the post is self-explanatory.

Drone (please complete the following information):
-Using Pixhawk Cube Black as hardware running this code

Additional context
None

[dagar]

To try and keep the full uorb top output to a reasonable length by default only topics with subscribers are printed.

https://github.com/PX4/Firmware/blob/cfcdab39929bd29c292082292b1c0824c0b75e29/src/modules/uORB/uORBDeviceMaster.cpp#L412

[js-motocrane]

Totally makes sense. I should have spent more time looking through the code. No issue then. I will close this.