actionlib and rqt

edit

Hello,

I'm learning ROS now and trying to create an action client in my rqt plugin.

No problem to catkin build the plugin. But when load the plugin, I got error as below:

undefined symbol: _ZN9actionlib17ConnectionMonitor21cancelConnectCallbackERKN3ros25SingleSubscriberPublisherE)

Unmangled:

actionlib::ConnectionMonitor::cancelConnectCallback(ros::SingleSubscriberPublisher const&)

My code is similar to the following. Is it a rqt bug, or is there anything wrong in my code?

Thank you for your help!

class MyPlugin : public rqt_gui_cpp::Plugin
    {
      Q_OBJECT
    public:
      MyPlugin();
      virtual void initPlugin(qt_gui_cpp::PluginContext& context);
      virtual void shutdownPlugin();
    private
      Ui::MyPluginWidget ui_;
      QWidget* widget_;
    actionlib::SimpleActionClient<my_msgs::MyAction> aClient;
    }

MyPlugin::MypPlugin()
: rqt_gui_cpp::Plugin()
, widget_(0)
, aClient("some action")
{
setObjectName("Plugin");
}