Installing ROS on an Kubuntu Cosmic (18.10) system by building from source

ros-install-ubuntu-cosmic.sh

# Source: http://wiki.ros.org/melodic/Installation/Source

function install_ros_first_time() {
    # Install bootstrap dependencies
    sudo apt-get install python-rosdep python-rosinstall-generator python-wstool python-rosinstall build-essential -y

    # Initialize rosdep
    sudo rosdep init
    rosdep update

    # Create catkin workspace folder
    mkdir ~/ros_catkin_ws
    cd ~/ros_catkin_ws

    # Install desktop-full version
    rosinstall_generator desktop_full --rosdistro melodic --deps --tar > melodic-desktop-full.rosinstall
    wstool init -j8 src melodic-desktop-full.rosinstall

    # Resolve missing dependencies
    rosdep install --from-paths src --ignore-src --os=ubuntu:bionic --rosdistro melodic -y

    # Build catkin workspace (release version)
    ./src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release

    # Add built ROS tools to path
    source ~/ros_catkin_ws/install_isolated/setup.bash
}

function update_ros_build() {
    cd ~/row_catkin_ws
    
    # Save old installation file
    mv -i melodic-desktop-full.rosinstall melodic-desktop-full.rosinstall.old
    
    # Generate new installation file
    rosinstall_generator desktop_full --rosdistro melodic --deps --tar > melodic-desktop-full.rosinstall
    
    # See difference between old and new install file
    diff -u melodic-desktop-full.rosinstall melodic-desktop-full.rosinstall.old
    
    # Incorporate new install file into workspace and update it
    wstool merge -t src melodic-desktop-full.rosinstall
    wstool update -t src
    
    # Rebuild workspace
    ./src/catkin/bin/catkin_make_isolated --install
    
    # Add rebuilt ROS tools to path
    source ~/ros_catkin_ws/install_isolated/setup.bash
}