NOTE: the directory containing all files (i.e. package.xml etc) must be called sim_ros_interface, otherwise build will fail.

1. Install required packages for libPlugin: see libPlugin's README
2. Checkout

$ git clone --recursive https://github.com/CoppeliaRobotics/simExtROS.git sim_ros_interface

3. Edit meta/messages.txt and meta/services.txt if you need to include more ROS messages/services. You need to specify the full message/service type, i.e. geometry_msgs/Twist rather than Twist.
4. Compile

$ catkin build

For ROS melodic / Ubuntu 18, use the 'melodic' branch