[SOLVED] Undefined Reference While Compiling ROS ORB

I am trying to compile this version of ORB SLAM2 and after fixing some library import errors, I got this:

CMakeFiles/Stereo.dir/src/ros_stereo.cc.o: In function `main':
ros_stereo.cc:(.text.startup+0xc49): undefined reference to `ORB_SLAM2::System::System(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ORB_SLAM2::System::eSensor, bool)'
collect2: error: ld returned 1 exit status
CMakeFiles/Stereo.dir/build.make:231: recipe for target '../Stereo' failed
make[2]: *** [../Stereo] Error 1
CMakeFiles/Makefile2:104: recipe for target 'CMakeFiles/Stereo.dir/all' failed
make[1]: *** [CMakeFiles/Stereo.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
CMakeFiles/MonoAR.dir/src/AR/ros_mono_ar.cc.o: In function `main':
ros_mono_ar.cc:(.text.startup+0xd88): undefined reference to `ORB_SLAM2::System::System(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ORB_SLAM2::System::eSensor, bool)'
collect2: error: ld returned 1 exit status
CMakeFiles/MonoAR.dir/build.make:313: recipe for target '../MonoAR' failed
make[2]: *** [../MonoAR] Error 1
CMakeFiles/Makefile2:499: recipe for target 'CMakeFiles/MonoAR.dir/all' failed
make[1]: *** [CMakeFiles/MonoAR.dir/all] Error 2
CMakeFiles/RGBD.dir/src/ros_rgbd.cc.o: In function `main':
ros_rgbd.cc:(.text.startup+0x111): undefined reference to `ORB_SLAM2::System::System(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ORB_SLAM2::System::eSensor, bool)'
collect2: error: ld returned 1 exit status
CMakeFiles/RGBD.dir/build.make:231: recipe for target '../RGBD' failed
make[2]: *** [../RGBD] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/RGBD.dir/all' failed
make[1]: *** [CMakeFiles/RGBD.dir/all] Error 2
CMakeFiles/Mono.dir/src/ros_mono.cc.o: In function `main':
ros_mono.cc:(.text.startup+0x111): undefined reference to `ORB_SLAM2::System::System(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, ORB_SLAM2::System::eSensor, bool)'
collect2: error: ld returned 1 exit status
CMakeFiles/Mono.dir/build.make:231: recipe for target '../Mono' failed
make[2]: *** [../Mono] Error 1
CMakeFiles/Makefile2:430: recipe for target 'CMakeFiles/Mono.dir/all' failed
make[1]: *** [CMakeFiles/Mono.dir/all] Error 2
Makefile:129: recipe for target 'all' failed
make: *** [all] Error 2

Here is what my ORB_SLAM2/Examples/ROS/ORB_SLAM2/CMakeLists.txt looks like:

cmake_minimum_required(VERSION 2.4.6)
include($ENV{ROS_ROOT}/core/rosbuild/rosbuild.cmake)

rosbuild_init()

IF(NOT ROS_BUILD_TYPE)
  SET(ROS_BUILD_TYPE Release)
ENDIF()

MESSAGE("Build type: " ${ROS_BUILD_TYPE})

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}  -Wall  -O3 -march=native ")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall  -O3 -march=native")

# Check C++11 or C++0x support
include(CheckCXXCompilerFlag)
CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
if(COMPILER_SUPPORTS_CXX11)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
   add_definitions(-DCOMPILEDWITHC11)
   message(STATUS "Using flag -std=c++11.")
elseif(COMPILER_SUPPORTS_CXX0X)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x")
   add_definitions(-DCOMPILEDWITHC0X)
   message(STATUS "Using flag -std=c++0x.")
else()
   message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
endif()

LIST(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/../../../cmake_modules)

find_package(OpenCV 3.0 QUIET)
if(NOT OpenCV_FOUND)
   find_package(OpenCV 2.4.3 QUIET)
   if(NOT OpenCV_FOUND)
      message(FATAL_ERROR "OpenCV > 2.4.3 not found.")
   endif()
endif()

find_package(Eigen3 3.1.0 REQUIRED)
find_package(Pangolin REQUIRED)

include_directories(
${PROJECT_SOURCE_DIR}
${PROJECT_SOURCE_DIR}/../../../
${PROJECT_SOURCE_DIR}/../../../include
${Pangolin_INCLUDE_DIRS}
)

set(LIBS 
${OpenCV_LIBS} 
${EIGEN3_LIBS}
${Pangolin_LIBRARIES}
${PROJECT_SOURCE_DIR}/../../../Thirdparty/DBoW2/lib/libDBoW2.so
${PROJECT_SOURCE_DIR}/../../../Thirdparty/g2o/lib/libg2o.so
${PROJECT_SOURCE_DIR}/../../../lib/libORB_SLAM2.so
-lboost_system
)

# Node for monocular camera
rosbuild_add_executable(Mono
src/ros_mono.cc
)

target_link_libraries(Mono
${LIBS}
-lboost_system
)

# Node for monocular camera (Augmented Reality Demo)
rosbuild_add_executable(MonoAR
src/AR/ros_mono_ar.cc
src/AR/ViewerAR.h
src/AR/ViewerAR.cc
)

target_link_libraries(MonoAR
${LIBS}
-lboost_system
)

# Node for stereo camera
rosbuild_add_executable(Stereo
src/ros_stereo.cc
)

target_link_libraries(Stereo
${LIBS}
-lboost_system
)

# Node for RGB-D camera
rosbuild_add_executable(RGBD
src/ros_rgbd.cc
)

target_link_libraries(RGBD
${LIBS}
-lboost_system
)

I tried to add Boost dependencies in the CMake file but nothing helps. I tried to recompile Boost for version 1.67 and recompiled OpenCV version 3.2. None of these things helped. Any help is appreciated!

Undefined Reference While Compiling ROS ORB_SLAM2