Depend on rosbag2_storage before pluginlib

[sloretz]

This fixes #583 for me. It puts the includes for rosbag2_storage before the includes for pluginlib. Because pluginlib is not in the overlay described in #583, the include path it adds first is /opt/ros/include. That causes it to find the includes for rosbag2_storage in /opt/ros/include, not the includes for the one built in install/rosbag2_storage/include.

Maybe this means things in ament_target_dependencies() should not automatically be alphabetized? It's not clear to me what should happen instead. Including packages in the same repo first makes sense, but what if I had an overlay workspace with ros2_storage_default_plugins from the release repo and pluginlib? Then the order added by this PR would be wrong. There probably needs to be a change in ament_target_dependencies() to reorder things so that things get depended on in workspace order no matter what.

@pjreed FYI

[emersonknapp]

Maybe this means things in ament_target_dependencies() should not automatically be alphabetized? It's not clear to me what should happen instead. Including packages in the same repo first makes sense, but what if I had an overlay workspace with ros2_storage_default_plugins from the release repo and pluginlib? Then the order added by this PR would be wrong. There probably needs to be a change in ament_target_dependencies() to reorder things so that things get depended on in workspace order no matter what.

I agree that it would be ideal for ament_target_dependencies to handle this for us.

That being said - this seems fine. Could you add a comment to the CMakelists explaining why it's necessary? Otherwise I can see somebody moving it without knowing it was intentional.

[Karsten1987]

@sloretz friendly ping. Is this still a problem?

[sloretz]

@sloretz friendly ping. Is this still a problem?

IIRC is solved the workspace overlay problem for this one particular situation, but I don't think it's possible to know the right order at the package level because it depends on what packages are in the underlay.

I think it makes sense to close this PR, and document it somewhere as a limitation with overlaying merged workspaces.