CMake adding opencv - c++

Question

I'm trying to include opencv2.4.9 with cmake:
cmake_minimum_required(VERSION 2.8.3)
project(HydroCamel)
SET(CMAKE_CXX_FLAGS "-lpthread")
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
std_msgs
)
catkin_package()
set(SRC_FOLDER src/src)
set(ALOGS_FOLDER src/Algos)
set(ALOGS_UTILS_FOLDER src/Algos/Utils)
set(SRC_INCLUDE_FOLDER src/include)
set(DIRS ${SRC_FOLDER} ${ALOGS_FOLDER} ${ALOGS_UTILS_FOLDER} ${SRC_INCLUDE_FOLDER})
include_directories(${DIRS})
file(GLOB_RECURSE SRC_FILES "*.h" "*.cpp")
include_directories(include ${catkin_INCLUDE_DIRS})
set(Boost_USE_STATIC_LIBS OFF)
set(Boost_USE_MULTITHREADED ON)
set(Boost_USE_STATIC_RUNTIME OFF)
find_package(Boost 1.55.0 COMPONENTS filesystem system thread)
#FIND_PACKAGE(OpenCV REQUIRED core imgproc highgui)
include_directories(${OpenCV_INCLUDE_DIRS})
if(Boost_FOUND)
include_directories(${Boost_INCLUDE_DIRS})
add_executable(SourceFiles ${SRC_FILES})
TARGET_LINK_LIBRARIES(SourceFiles ${Boost_LIBRARIES})
TARGET_LINK_LIBRARIES(SourceFiles ${OpenCV_LIBS})
endif()
And I receive this error:
CMake Error at HydroCamel/CMakeLists.txt:28 (find_package): Found
package configuration file:
/home/jdorfsman/opencv-2.4.9/build/OpenCVConfig.cmake
but it set OpenCV_FOUND to FALSE so package "OpenCV" is considered
to be NOT FOUND.
-- Configuring incomplete, errors occurred! See also "/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeOutput.log". See also
"/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeError.log".
This is the CMakeError.log file:
Determining if the pthread_create exist failed with the following output:
Change Dir: /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp
Run Build Command:/usr/bin/make "cmTryCompileExec1061744568/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec1061744568.dir/build.make CMakeFiles/cmTryCompileExec1061744568.dir/build
make[1]: Entering directory `/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec1061744568.dir/CheckSymbolExists.c.o
/usr/bin/cc -o CMakeFiles/cmTryCompileExec1061744568.dir/CheckSymbolExists.c.o -c /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTryCompileExec1061744568
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec1061744568.dir/link.txt --verbose=1
/usr/bin/cc CMakeFiles/cmTryCompileExec1061744568.dir/CheckSymbolExists.c.o -o cmTryCompileExec1061744568 -rdynamic
CMakeFiles/cmTryCompileExec1061744568.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0x16): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
make[1]: *** [cmTryCompileExec1061744568] Error 1
make[1]: Leaving directory `/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp'
make: *** [cmTryCompileExec1061744568/fast] Error 2
File /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>
int main(int argc, char** argv)
{
(void)argv;
#ifndef pthread_create
return ((int*)(&pthread_create))[argc];
#else
(void)argc;
return 0;
#endif
}
Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp
Run Build Command:/usr/bin/make "cmTryCompileExec3426763052/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec3426763052.dir/build.make CMakeFiles/cmTryCompileExec3426763052.dir/build
make[1]: Entering directory `/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec3426763052.dir/CheckFunctionExists.c.o
/usr/bin/cc -DCHECK_FUNCTION_EXISTS=pthread_create -o CMakeFiles/cmTryCompileExec3426763052.dir/CheckFunctionExists.c.o -c /usr/share/cmake-2.8/Modules/CheckFunctionExists.c
Linking C executable cmTryCompileExec3426763052
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec3426763052.dir/link.txt --verbose=1
/usr/bin/cc -DCHECK_FUNCTION_EXISTS=pthread_create CMakeFiles/cmTryCompileExec3426763052.dir/CheckFunctionExists.c.o -o cmTryCompileExec3426763052 -rdynamic -lpthreads
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
make[1]: *** [cmTryCompileExec3426763052] Error 1
make[1]: Leaving directory `/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp'
make: *** [cmTryCompileExec3426763052/fast] Error 2

Answer 1

Looks like you don't specify the pthread flag.
CMakeFiles/cmTryCompileExec1061744568.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0x16): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
make[1]: *** [cmTryCompileExec1061744568] Error 1
make[1]: Leaving directory `/home/jdorfsman/catkin_ws/build/CMakeFiles/CMakeTmp'
make: *** [cmTryCompileExec1061744568/fast] Error 2
try add:
SET(CMAKE_CXX_FLAGS "-lpthread")