我对ROS相对较新，并且一直在学习这些教程。当我输入命令rosrun rqt_plot rqt_plot时跟随链接http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics。我收到以下错误。什么意思？
PluginManager._discover() force discovery of plugins
RospkgPluginProvider._find_plugins() crawling for plugins of type 'qt_gui'
Could not import "pyside" bindings of qt_gui_cpp library - so C++ plugins will not be available:
Traceback (most recent call last):
File "/opt/ros/kinetic/lib/python2.7/dist-packages/qt_gui_cpp/cpp_binding_helper.py", line 39, in <module>
from . import libqt_gui_cpp_shiboken
ImportError: dynamic module does not define module export function (PyInit_libqt_gui_cpp_shiboken)
RospkgPluginProvider._find_plugins() crawling for plugins of type 'rqt_gui'
QtBindingHelper using pyside
PerspectiveManager.switch_perspective() switching to perspective "@rqt_plot__Plot"
MainWindow.restore_settings()
PluginManager.restore_settings_without_plugins()
MainWindow.restore_state()
PluginManager.load_plugin(rqt_plot/Plot, 0)
MainWindow.save_setup()
RosPyPluginProvider._init_node() initialize ROS node "rqt_gui_py_node_18124"
QWidget: Must construct a QApplication before a QPaintDevice
Aborted (core dumped)