Undefined symbol in custom costmap layer during runtime caused by tf2 Buffer transform

edit

I am writing a custom costmap layer to read data from a radar sensor and turn it into a costmap, and I'm facing some issues running it. I get the following error when it runs:

symbol lookup error: /home/mkhoory/sdc/catkin_ws/devel/lib//libRadarDataLayer.so: undefined symbol: _ZN3tf212getTimestampIN13geometry_msgs15PolygonStamped_ISaIvEEEEERKN3ros4TimeERKT_

What the related code is trying to do is create a PolygonStamped from the radar data and convert it to world coordinates via tf2.

tfBuffer.transform(polyRadar, polyWorld, globalFrame);

I'm not sure what I'm doing wrong here. The code compiles fine, and it's only when the plugin reaches the above line that it tells me that it's an undefined reference. I tried including tf2_geometry_msgs.h but that didn't do anything. What am I missing?

EDIT: Here's my CMakeLists.txt:

cmake_minimum_required(VERSION 2.8.3)
project(my_project_processing)

find_package(catkin REQUIRED COMPONENTS
  roscpp
  rospy
  std_msgs
  geometry_msgs
  message_generation
  tf
  tf2
  tf2_geometry_msgs
  costmap_2d
  dynamic_reconfigure
  my_project_sensors
)

find_package(Boost REQUIRED COMPONENTS system thread)

add_message_files(
    FILES
    CommandMessage.msg
)

generate_messages(
  DEPENDENCIES
  std_msgs
  geometry_msgs
)

catkin_package(
  INCLUDE_DIRS include
  LIBRARIES
  CATKIN_DEPENDS roscpp rospy std_msgs tf message_runtime geometry_msgs message_generation
  DEPENDS Boost
)

# let's use C++11
SET(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS}")

include_directories(
  include
  ${tf2_INCLUDE_DIRS}
  ${catkin_INCLUDE_DIRS}
  ${Boost_INCLUDE_DIRS}
)

# Costmap2D Layer plugin
add_library(RadarDataLayer lib/RadarDataLayer.cpp)
target_link_libraries(RadarDataLayer ${Boost_LIBRARIES} ${catkin_LIBRARIES})