This package works with the xArm6 and EZgripper by SAKE Robotics and is to be used in conjuction with both of modified repos made by me (https://github.com/dkoh555/mod_old_xarm_ros) and (https://github.com/dkoh555/gripper_control) respectively.
Make sure to install the above mentioned packages first (clone them into your workspace and then catkin_make BEFORE you clone in the arm_control package to catkin_make). This is because of the alphabetical order of the packages that catkin_make will build, it will build arm_controller first, but it relies on dependencies that need to first be generated by the other two packages.