# Revision history [back]

catkin_create_pkg needs to know what ROS distribution you're using. If you have sourced a ROS setup script, it can detect it automatically. If you haven't sourced a setup script, you need to pass it in as a command line argument. You have two options:

1. Source the setup script before you try to run catkin_create_pkg:

source /opt/ros/indigo/setup.bash
catkin_create_pkg firstpackage std_msgs rospy roscpp

2. Pass the rosdistro into the catkin_create_pkg command with the flag:

catkin_create_pkg firstpackage std_msgs rospy roscpp


P.S. When posting on ROS Answers, you can format code blocks (like the ones I used above) with the 101010 button in the toolbar, and you can format inline code blocks like this by surrounding it with backticks like this.