I have cloned packages for an ROS based robot called Chefbot from This Github repository and copied the chefbot folder from the cloned files, into my catkin workspace src folder as per the instructions of the developer. This project is based on ROS Kinetic and I am running ROS Melodic. When I source my updated workspace after doing this, I am getting the following error output:

shaunak@robokits:~/catkin_ws$ rosdep install -y --from-paths src --ignore-src --rosdistro melodic  --os=ubuntu:bionic
ERROR: the following packages/stacks could not have their rosdep keys resolved
to system dependencies:
chefbot_bringup: Cannot locate rosdep definition for [depthimage_to_laserscan]
chefbot_gazebo: Cannot locate rosdep definition for [create_node]
chefbot_description: Cannot locate rosdep definition for [create_description]

I also tried rosdep install --from-paths src --ignore-src --rosdistro=melodic -y -r to ignore the errors and initiate catkin_make_isolated --force-cmake(I am not using catkin_make as it does not work for other packages) but it throws an error of not being able to process the package. I am sure that the packages run without errors in ROS Kinetic. So I have to resolve this particular package's ROS version compatibility issue which is actually not there as per The Discussion Here, I am convinced with it and hence I have a few questions:

1. Which files in any ROS package do depend on the version of ROS?
2. Which segments in files referred in Question 1 do depend on the version of ROS?
3. How does the environment of the ROS version affect these segments referred in Question 2?
4. What can be done to make the environment of the ROS flexible so that the segments and hence the files do not get affected with the version-change?

The questions may sound silly as I am a beginner, but I have been facing the issues considering a fact that ROS Melodic is the latest release. In fact, there is not a problem with a version-change in general, but sometimes this kind of issue pops up where things are not happening with other developer's open source package with different ROS version. So the answers to these questions may be helpful.

Edit 1 with reference to the Answer 1 (below) from @l4ncelot :

I followed the steps suggested in Answer 1 by cloning the package depthimage_to_lasercan from the source link given Here to my catkin workspace, sourcing the workspace and then applying catkin_make, but I am getting the following error output:

error: expected constructor, destructor, or type conversion before  ' ( ' token
 PLUGINLIB_DECLARE_CLASS(depthimage_to_laserscan, DepthImageToLaserScanNodelet,  
 depthimage_to_laserscan::DepthImageToLaserScanNodelet, nodelet::Nodelet);
                         ^
depthimage_to_laserscan/CMakeFiles/DepthImageToLaserScanNodelet.dir/build.make:62: recipe for target 'depthimage_to_laserscan/CMakeFiles/DepthImageToLaserScanNodelet.dir/src/DepthImageToLaserScanNodelet.cpp.o' failed

This seems to be more of a syntax error which I am not able to solve. I went to the Bug / feature tracker link of the package given Here, but could not get much out of it.

Edit 2 with reference to comment from @l4ncelot :

Comment Number 4 -->

@Shaunak Vyas doesn't matter if it's has been released yet or not. Just get the pull request (or edit you code by yourself according to [this](https://github.com/ros-perception/depthimage_to_laserscan/pull/27/commits/6394008e59c95773750e48ff90efd4d0f5c95db3) commit) and it should fix the error.

Thank you for this. After getting so many missing packages, it fixed the error indeed. Now I am able to execute rosdep install -y --from-paths src --ignore-src successfully. But when I apply catkin_make_isolated --force-cmake, I am dealing with the following error output:

    -- Could NOT find kobuki_description (missing: kobuki_description_DIR)
    -- Could not find the required component 'kobuki_description'. The following CMake error indicates that you either need to install the package with the same name or change your environment so that it can be found.
    CMake Error at /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
      Could not find a package configuration file provided by
      "kobuki_description" with any of the following names:

        kobuki_descriptionConfig.cmake
        kobuki_description-config.cmake

      Add the installation prefix of "kobuki_description" to CMAKE_PREFIX_PATH or
      set "kobuki_description_DIR" to a directory containing one of the above
      files.  If "kobuki_description" provides a separate development package or
      SDK, be sure it has been installed.
    Call Stack (most recent call first):
      CMakeLists.txt:7 (find_package)
    -- Configuring incomplete, errors occurred!
<== Failed to process package 'chefbot_description'

Tried to google the error statement "Could not find a package configuration file" and got to know that there are many people facing the same error, but the solution depends on the package and hence it's not generalized.

Edit 3 based on few failed experiments :

As the error stated in Edit 2 was not getting resolved even after escalating the issue Here, I applied a new approach by removing the Chefbot package from my workspace because I wanted to check whether the standard packages get built or not. Now I am having a workspace that has all the required packages for Chefbot and the command rosdep install -y --from-paths src --ignore-src --rosdistro melodic --os=ubuntu:bionic runs successfully by giving output #All required rosdeps installed successfully without even a single warning. That means my dependencies are correct. But I am stuck at an error when applying catkin_make_isolated --force-cmake and I have escalated the issue Here. The error that I am getting seems like a programming error and hence I can not do anything except waiting for the package developer to resolve it.

Note: I have cloned each and every package into my workspace from the ROS Wiki source link of the package only.

• Shaunak Agastya Vyas (TINU)

Here is the package you need. Do the same thing like with other catkin package i.e. clone to workspace, build, source.

rosdep install -y --from-paths src --ignore-src --rosdistro melodic  --os=ubuntu:bionic

#All required rosdeps installed successfully

chefbot_bringup: Cannot locate rosdep definition for [depthimage_to_laserscan]