How can I get my cout output on the console with roslaunch

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Why does only error output appear at the console when launching a ros node from roslaunch? Also, I can I force the normal behavior, so that I can see my cout output?

For example, I wrote this in a simple node:

ROS_INFO("ROS_INFO");
ROS_WARN("ROS_WARN");
ROS_ERROR("ROS_ERROR");
std::cout << "cout" << std::endl;
std::cerr << "cerr" << std::endl;

If I call rosrun myNode myNode, I see the five lines. If I call roslaunch myNodeLauncher, I see only ROS_ERROR and std::cerr.