Cannot get ROS_INFO output in callback function [closed]

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Hi, I'm new to ROS and I'm trying to subscribe to the pose of a moving turtle and print it out. I believe I subscribed to the right topic but there is no ouput for ROS_INFO in callback function. Anyone can help? Thanks.

#include <ros/ros.h>
#include <turtlesim/Pose.h> 
void poseCallback(const turtlesim::PoseConstPtr& msg)
{

    ROS_INFO("%f %f %f", msg->x, msg->y, msg->theta);
}

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

    ros::init(argc, argv, "hw1_turtle2_listener");

    ros::NodeHandle node;
    ros::Subscriber sub = node.subscribe("turtle2/pose", 10, &poseCallback);

    ros::spin();

    eturn 0;
};