rospy node receives no messages

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I have a node which regularly publishes on some topic. I can use rostopic to monitor this and confirm that messages are being published.

I wanted to add a rospy-based Python node that subscribes to this topic. So I aped the tutorial code and only modified it to subscribe to the appropriate topic.

roslaunch property starts my Python node and doesn't report any errors. rosnode info <node> tells me that indeed the Python node subscribed to the topic. But rostopic echo /rosout does not show that node outputting anything, so:

• Messages aren't being received by the Python node, OR
• Log messages aren't being written to /rosout

What can I do to diagnose further?