Output of roswtf for "automatic takeoff and landing" tutorial as it is (http://docs.erlerobotics.com/simulation/vehicles/erle_copter/tutorial_3)

roswtf

prasad@prasad-Lenovo-Y50-70:~$ source ~/simulation/ros_catkin_ws/devel/setup.bash
prasad@prasad-Lenovo-Y50-70:~$ roswtf 
Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING You have pip installed packages on Ubuntu, remove and install using Debian packages: catkin_pkg -- 

================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules
running tf checks, this will take a second...
... tf checks complete

Online checks summary:

Found 2 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /mavros:
   * /mavros/setpoint_raw/global
   * /mavros/setpoint_raw/attitude
   * /mavros/setpoint_velocity/cmd_vel
   * /mavros/setpoint_position/local
   * /tf_static
   * /mavlink/to
   * /mavros/rc/override
   * /mavros/setpoint_raw/local
   * /mavros/setpoint_accel/accel
 * /gazebo:
   * /gazebo/set_link_state
   * /erlecopter/waypoint
   * /imu
   * /command/motors
   * /erlecopter/wind
   * /command/rate
   * /erlecopter/command/attitude
   * /gazebo/set_model_state

WARNING These nodes have died:
 * spawn_erlecopter-3


prasad@prasad-Lenovo-Y50-70:~$