permission denied when creating custom msg in rosserial

edit

rosrun rosserial_client make_library.py /usr/share/arduino/libraries encoders

I get the following error. But it did create Encoder.h in /usr/share/arduino/libraries/ros_lib/Encoder so I guess I'm ok?

Exporting to /usr/share/arduino/libraries/ros_lib
['encoders', 'rospack', 'roslib', 'std_msgs', 'rosgraph_msgs', 'rosbuild', 'roslang', 'rospy']
Exporting encoders
  Messages:
    Encoder, 

  Services:

Exporting rospack
  Messages:

  Services:

Exporting roslib
  Messages:

  Services:

Exporting std_msgs
  Messages:
    UInt32, UInt32MultiArray, Header, Int16MultiArray, Bool, Int8, Int32MultiArray, Float32MultiArray, Byte, Char, UInt16, Float64, Int32, MultiArrayLayout, Int64MultiArray, String, UInt8MultiArray, UInt64, UInt8, Int16, Time, Int64, MultiArrayDimension, ColorRGBA, UInt16MultiArray, Empty, Int8MultiArray, UInt64MultiArray, Duration, ByteMultiArray, Float64MultiArray, Float32, 

  Services:

Traceback (most recent call last):
  File "/opt/ros/electric/stacks/rosserial/rosserial_client/src/rosserial_client/make_library.py", line 582, in <module>
    MakeLibrary(package, path)
  File "/opt/ros/electric/stacks/rosserial/rosserial_client/src/rosserial_client/make_library.py", line 548, in MakeLibrary
    header = open(output_path + "/" + msg.name + ".h", "w")
IOError: [Errno 13] Permission denied: '/usr/share/arduino/libraries/ros_lib/std_msgs/UInt32.h'