Couldn't find an AF_INET address for []

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Hi @Patrickelectric ,

that happens because you have to call ros::init() BEFORE the instantiation of your ros::NodeHandle.

As an example, If you compile the code below (from Writing a Simple Publisher and Subscriber tutorial ), as is, it will work because ros::init is being called first. But if you uncomment the nodeBeforeRosInitWillFail node, you will see that this error happens since ros::init is called AFTER nodeBeforeRosInitWillFail.

#include "ros/ros.h"
#include "std_msgs/String.h"

#include <sstream>

int main(int argc, char **argv)
{

  /**
   * Definining a ros::NodeHandle before ros::init causes the error
   * To confirm that, just uncomment the  nodeBeforeRosInitWillFail node below
   */
  //ros::NodeHandle nodeBeforeRosInitWillFail;

  ros::init(argc, argv, "talker");

  ros::NodeHandle n;

  ros::Publisher chatter_pub = n.advertise<std_msgs::String>("chatter", 1000);

  ros::Rate loop_rate(10);

  int count = 0;
  while (ros::ok())
  {

    std_msgs::String msg;

    std::stringstream ss;
    ss << "hello world " << count;
    msg.data = ss.str();

    ROS_INFO("%s", msg.data.c_str());

    chatter_pub.publish(msg);

    ros::spinOnce();

    loop_rate.sleep();
    ++count;
  }
  return 0;
}

You can see this example in the following video ( https://youtu.be/UsuQwUkzNII ) if you prefer.