[ros-users] Nodelet .so dependencies

[Andy Somerville]

On Tue, Dec 14, 2010 at 7:02 PM, Andy Somerville
<andy.somerville at resquared.com> wrote:
> 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

oops I managed to hit send without adding this:

[ERROR] [1292371444.983882442]: Failed to call service!
[standalone_nodelet-1] process has died [pid 8496, exit code 127].



>
> 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
>

Also I adapted my launch file from nodelet_tutorial_math so I'm not
certain I'm launching correctly. Here's my launchfile:

<launch>
  <node pkg="nodelet" type="nodelet" name="standalone_nodelet"
args="manager" output="screen"/>
  <node pkg="nodelet" type="nodelet" name="VideoNodelet" args="load
video_nodelet/VideoNodelet standalone_nodelet" output="screen"/>
</launch>



     Andy