rqt package - plugin not found

edit

Following the tutorial to create an rqt plugin, trying to run the plugin

rqt --force-discover -s rqt_mypkg

returns

qt_gui_main() found no plugin matching "rqt_mypkg"
try passing the option "--force-discover"

This same command, however, is able to run plugins like rqt_bags etc.

The plugin is also not visible when running

rqt --list-plugins

I have tried all other solutions here, including deleting the rqt cache, running rqt and then selecting the plugin (the plugin does not appear).

For reference,

rosversion qt_gui && rosversion rqt_gui

gives 0.3.11 and 0.5.0, and rospack find returns my package path as expected.

My package.xml file looks like...

<?xml version="1.0"?>
<package format="2">
  <name>rqt_mypkg</name>
  <version>0.0.0</version>
  <description>The rqt_mypkg package</description>

  <maintainer email="jane.doe@example.com">Jane Doe</maintainer>

  <license>TODO</license>

  <buildtool_depend>catkin</buildtool_depend>

  <build_depend>rospy</build_depend>
  <build_depend>rqt_gui</build_depend>
  <build_depend>rqt_gui_py</build_depend>

  <build_export_depend>rospy</build_export_depend>
  <build_export_depend>rqt_gui</build_export_depend>
  <build_export_depend>rqt_gui_py</build_export_depend>

  <exec_depend>rospy</exec_depend>
  <exec_depend>rqt_gui</exec_depend>
  <exec_depend>rqt_gui_py</exec_depend>

  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->
    <export>
      <architecture_independent/>
      <rqt_gui plugin="${prefix}/plugin.xml"/>
    </export>
  </export>
</package>

EDIT: this was resolved by importing and running the complete tutorial found here. Running the original code after doing this didn't encounter any errors. Not that that really explains anything...