[ros-users] Nodelet .so dependencies

[Andy Somerville]

I've been creating a sample project to get myself comfortable with the
nodelet/pluginlib context lately. In doing so I've come across the
following problem:

When running my nodelet it fails to start with the an error message
indicating it's having trouble locating a symbol within one of its
dependencies:

    /opt/ros/cturtle/stacks/common/nodelet/bin/nodelet: symbol lookup
error: /home/somervil/Projects/rdk2context/stacks/video_nodelet/lib/libvideonodelet.so:
undefined symbol:
_Z20usb_cam_camera_startPKc17usb_cam_io_method20usb_cam_pixel_formatii

and then

I know the following:
  * My nodelet is dependent on usb_cam which I have listed as a
dependency in the manifest.
  * libusb_cam.so is where the offending undefined symbol should live.
  * libusb_cam.so has been build and exists in usb_cam/lib
  * usb_cam is in the ROS_PACKAGE_PATH
  * usb_cam is exporting it's relevant path

It's unclear to me how the nodelet/plugin system would be aware of a
nodelet's dependencies, and where to look for them, thus explaining
the problem I'm seeing. But since I haven't seem other people raise
the issue, I imagine I must be doing something wrong.

The only think I can imagine is that I'm supposed to be passing the
dependencies to the nodelets manager but in looking in the nodelet
code, that doesn't seem to be correct.



TL;DR: Does anyone know how to supply the nodelet manager with the
info it needs to resolve symbols from dependencies?


     Andy Somerville