rqt_graph can't start

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Noob here. I have been following the ROS tutorials up to http://wiki.ros.org/ROS/Tutorials/Und... with no apparent problems.

But when I try to run rqt:

rosrun rqt_graph rqt_graph

All I get is the following:

 Traceback (most recent call last):
      File "/opt/ros/kinetic/bin/rqt_graph", line 5, in <module>
        from rqt_gui.main import Main
 ImportError: No module named rqt_gui.main

apt-get says ros-kinetic-rqt and ros-kinetic-rqt-common-plugins are already up to date, and I have tried rebooting the system, rolling back python pip, and running it with and without roscore. What do I need to do to get rqt_graph to work?