Hey,

Up until now, we've been doing an awkward scheme of one roslaunch file per
machine, which has meant that they only ever have to launch local nodes.
However, I'm trying to clean it up to take advantage of roslaunch's
remote-start abilities.

I have it mostly working, but there's one little annoyance:

<launch>
  <include file="machines.launch" />

  <group ns="clearpath/robots/default">
    <node pkg="joy" type="joy_node" name="joy_node" output="screen">
      <param name="dev" value="/dev/input/js0" />
    </node>

    <node pkg="clearpath_horizon" type="joy.py" name="joy_horizon"
output="screen">
      <param name="turn_scale" value="1.2" />
      <param name="drive_scale" value="0.5" />
    </node>

    <node pkg="clearpath_horizon" type="horizon.py" name="horizon"
machine="cpr-demo-01" respawn="true" output="screen">
      <!-- Type of commands given: velocity control v. output control -->
      <param name="velocity_control" value="1" />

      <!-- Horizon data request frequencies -->
      <param name="data/differential_output" value="10" />
      <param name="data/system_status" value="10" />
      <param name="data/power_status" value="1" />
    </node>
  </group>
</launch>

Now, this works great when I launch it on my developer desktop--- I get a
joy_node and a joy_horizon coming up locally, and horizon comes up on the
cpr-demo-01 machine, and I can joystick around our chassis.

However, I like to be able to plug the joystick into the cpr-demo-01 machine
and actually run it all from there, too. It seems like this should be
possible, but when I try it, the horizon comes up with a Python include
error--- it can't find roslib, of all things. This error doesn't show when I
run it remotely, and it's also fine if I remove the
machine="cpr-demo-01" part.

Is this documented behaviour, or am I doing something wrong? It would be
really convenient if this could be made to work without having to maintain
separate files for whether the joystick is onboard the robot or off-board.

Thanks,

Mike