compile issue

[BrutusTT]

Installing WCS in a fresh workspace gives the following error:

-- +++ processing catkin package: 'communication_node'
-- ==> add_subdirectory(WCS/communication_node)
-- Using these message generators: gencpp;geneus;genlisp;gennodejs;genpy
-- Generating .msg files for action communication_node/Registration /home/ubuntu/catkin_ws/src/WCS/communication_node/action/Registration.action
CMake Error at /opt/ros/kinetic/share/genmsg/cmake/genmsg-extras.cmake:263 (message):
Messages depends on unknown pkg: sample_packages (Missing
'find_package(sample_packages)'?)
Call Stack (most recent call first):
WCS/communication_node/CMakeLists.txt:89 (generate_messages)

It seems to me that the communication_node depends on sample_packages, but adding it as a build dependency (package.xml) gives a circular dependency error. On the other side, removing the dependency in the CMakeList.txt of the communication_node gives compilation errors in the that package.

How do I break the cycle properly?

[MH-Bravo-Six]

The core functionality of WCS lies with communication_node and gazebo_information_plugins.
the sole purpose of sample_package is showing how to use APIs provided by communication_node and containing some sample codes,hence its name.Therefore, you don't really need sample_package to use WCS as long as you can use APIs according to the tutorial. Also, note that communication_node depends on sample_package because some message files in communication_node/msg depend on message files in sample_package/msg. One naive solution is to modify CMakeList.txt of communication_node so that it no longer compiles the message files that depend on sample_package. Be aware, with this solution you won't be able to use example scripts and codes in sample_package.

As of June 15th, I've updated WCS with some minor debugging. Now, sample_package no longer depends on communication_node. I compiled sample_package first, and then the whole WCS without any problem.

As a better and proper solution, I suggest you to clone WCS again and try to compile only the sample_package. After successful compilation of sample_package you can then try to compile the whole WCS.

[taherahmadi]

The circular dependency resolved, please check it again.

the main reason for putting a sample_package there is if you are going to send some custom data (something that is not already provided in communication_node package) between your robots, find out how to import your custom msg into communication_node.
in that order, you need to define your msg like sample_message.msg in sample_package/msg then create a new message in the communication_node package and similar to Data_sample.msg in communication_node/msg, put your message as an entry in that file.

• in case of distance_service.h error just attemp to build again.