title: Cannot compile opencv
body: <p>I am trying to compile opencv from source</p>
  
  <pre><code>git clone https://github.com/berak/opencv.git
  </code></pre>
  
  <p>While performing 'make', I get following error. I found similar issue <a href="https://github.com/airdcnano/airdcnano/issues/5" rel="nofollow">here</a> but I don't understand what is going on and how to solve it</p>
  
  <pre><code>error: conflicting types for '__sigsetjmp'
  extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __THROWNL;
         ^
  /usr/include/pthread.h:754:12: note: previous declaration is here
  extern int __sigsetjmp (struct __jmp_buf_tag *__env, int __savemask) __THROWNL;
         ^
  1 error generated.
  </code></pre>
  
  <p>The output from cmake . is</p>
  
  <pre><code>-- The CXX compiler identification is GNU 4.9.2
  -- The C compiler identification is GNU 4.9.2
  -- Check for working CXX compiler: /usr/bin/g++
  -- Check for working CXX compiler: /usr/bin/g++ -- works
  -- Detecting CXX compiler ABI info
  -- Detecting CXX compiler ABI info - done
  -- Check for working C compiler: /usr/bin/cc
  -- Check for working C compiler: /usr/bin/cc -- works
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - done
  -- Detected version of GNU GCC: 49 (409)
  -- Performing Test HAVE_CXX_FSIGNED_CHAR
  -- Performing Test HAVE_CXX_FSIGNED_CHAR - Success
  -- Performing Test HAVE_C_FSIGNED_CHAR
  -- Performing Test HAVE_C_FSIGNED_CHAR - Success
  -- Performing Test HAVE_CXX_W
  -- Performing Test HAVE_CXX_W - Success
  -- Performing Test HAVE_C_W
  -- Performing Test HAVE_C_W - Success
  -- Performing Test HAVE_CXX_WALL
  -- Performing Test HAVE_CXX_WALL - Success
  -- Performing Test HAVE_C_WALL
  -- Performing Test HAVE_C_WALL - Success
  -- Performing Test HAVE_CXX_WERROR_RETURN_TYPE
  -- Performing Test HAVE_CXX_WERROR_RETURN_TYPE - Success
  -- Performing Test HAVE_C_WERROR_RETURN_TYPE
  -- Performing Test HAVE_C_WERROR_RETURN_TYPE - Success
  -- Performing Test HAVE_CXX_WERROR_NON_VIRTUAL_DTOR
  -- Performing Test HAVE_CXX_WERROR_NON_VIRTUAL_DTOR - Success
  -- Performing Test HAVE_C_WERROR_NON_VIRTUAL_DTOR 
  -- Performing Test HAVE_C_WERROR_NON_VIRTUAL_DTOR - Success
  -- Performing Test HAVE_CXX_WERROR_ADDRESS
  -- Performing Test HAVE_CXX_WERROR_ADDRESS - Success
  -- Performing Test HAVE_C_WERROR_ADDRESS
  -- Performing Test HAVE_C_WERROR_ADDRESS - Success
  -- Performing Test HAVE_CXX_WERROR_SEQUENCE_POINT
  -- Performing Test HAVE_CXX_WERROR_SEQUENCE_POINT - Success
  -- Performing Test HAVE_C_WERROR_SEQUENCE_POINT
  -- Performing Test HAVE_C_WERROR_SEQUENCE_POINT - Success
  -- Performing Test HAVE_CXX_WFORMAT
  -- Performing Test HAVE_CXX_WFORMAT - Success
  -- Performing Test HAVE_C_WFORMAT
  -- Performing Test HAVE_C_WFORMAT - Success
  -- Performing Test HAVE_CXX_WERROR_FORMAT_SECURITY
  -- Performing Test HAVE_CXX_WERROR_FORMAT_SECURITY - Success
  -- Performing Test HAVE_C_WERROR_FORMAT_SECURITY
  -- Performing Test HAVE_C_WERROR_FORMAT_SECURITY - Success
  -- Performing Test HAVE_CXX_WMISSING_DECLARATIONS
  -- Performing Test HAVE_CXX_WMISSING_DECLARATIONS - Success
  -- Performing Test HAVE_C_WMISSING_DECLARATIONS
  -- Performing Test HAVE_C_WMISSING_DECLARATIONS - Success
  -- Performing Test HAVE_CXX_WMISSING_PROTOTYPES
  -- Performing Test HAVE_CXX_WMISSING_PROTOTYPES - Failed
  -- Performing Test HAVE_C_WMISSING_PROTOTYPES
  -- Performing Test HAVE_C_WMISSING_PROTOTYPES - Success
  -- Performing Test HAVE_CXX_WSTRICT_PROTOTYPES
  -- Performing Test HAVE_CXX_WSTRICT_PROTOTYPES - Failed
  -- Performing Test HAVE_C_WSTRICT_PROTOTYPES
  -- Performing Test HAVE_C_WSTRICT_PROTOTYPES - Success
  -- Performing Test HAVE_CXX_WUNDEF
  -- Performing Test HAVE_CXX_WUNDEF - Success
  -- Performing Test HAVE_C_WUNDEF
  -- Performing Test HAVE_C_WUNDEF - Success
  -- Performing Test HAVE_CXX_WINIT_SELF
  -- Performing Test HAVE_CXX_WINIT_SELF - Success
  -- Performing Test HAVE_C_WINIT_SELF
  -- Performing Test HAVE_C_WINIT_SELF - Success
  -- Performing Test HAVE_CXX_WPOINTER_ARITH
  -- Performing Test HAVE_CXX_WPOINTER_ARITH - Success
  -- Performing Test HAVE_C_WPOINTER_ARITH
  -- Performing Test HAVE_C_WPOINTER_ARITH - Success
  -- Performing Test HAVE_CXX_WSHADOW
  -- Performing Test HAVE_CXX_WSHADOW - Success
  -- Performing Test HAVE_C_WSHADOW
  -- Performing Test HAVE_C_WSHADOW - Success
  -- Performing Test HAVE_CXX_WSIGN_PROMO
  -- Performing Test HAVE_CXX_WSIGN_PROMO - Success
  -- Performing Test HAVE_C_WSIGN_PROMO
  -- Performing Test HAVE_C_WSIGN_PROMO - Failed
  -- Performing Test HAVE_CXX_WNO_NARROWING
  -- Performing Test HAVE_CXX_WNO_NARROWING - Success
  -- Performing Test HAVE_C_WNO_NARROWING
  -- Performing Test HAVE_C_WNO_NARROWING - Success
  -- Performing Test HAVE_CXX_WNO_DELETE_NON_VIRTUAL_DTOR
  -- Performing Test HAVE_CXX_WNO_DELETE_NON_VIRTUAL_DTOR - Success
  -- Performing Test HAVE_C_WNO_DELETE_NON_VIRTUAL_DTOR
  -- Performing Test HAVE_C_WNO_DELETE_NON_VIRTUAL_DTOR - Failed
  -- Performing Test HAVE_CXX_WNO_UNNAMED_TYPE_TEMPLATE_ARGS
  -- Performing Test HAVE_CXX_WNO_UNNAMED_TYPE_TEMPLATE_ARGS - Failed
  -- Performing Test HAVE_C_WNO_UNNAMED_TYPE_TEMPLATE_ARGS
  -- Performing Test HAVE_C_WNO_UNNAMED_TYPE_TEMPLATE_ARGS - Failed
  -- Performing Test HAVE_CXX_FDIAGNOSTICS_SHOW_OPTION
  -- Performing Test HAVE_CXX_FDIAGNOSTICS_SHOW_OPTION - Success
  -- Performing Test HAVE_C_FDIAGNOSTICS_SHOW_OPTION
  -- Performing Test HAVE_C_FDIAGNOSTICS_SHOW_OPTION - Success
  -- Performing Test HAVE_CXX_WNO_LONG_LONG
  -- Performing Test HAVE_CXX_WNO_LONG_LONG - Success
  -- Performing Test HAVE_C_WNO_LONG_LONG
  -- Performing Test HAVE_C_WNO_LONG_LONG - Success
  -- Performing Test HAVE_CXX_PTHREAD
  -- Performing Test HAVE_CXX_PTHREAD - Success
  -- Performing Test HAVE_C_PTHREAD
  -- Performing Test HAVE_C_PTHREAD - Success
  -- Performing Test HAVE_CXX_FOMIT_FRAME_POINTER
  -- Performing Test HAVE_CXX_FOMIT_FRAME_POINTER - Success
  -- Performing Test HAVE_C_FOMIT_FRAME_POINTER
  -- Performing Test HAVE_C_FOMIT_FRAME_POINTER - Success
  -- Performing Test HAVE_CXX_MSSE
  -- Performing Test HAVE_CXX_MSSE - Success
  -- Performing Test HAVE_C_MSSE
  -- Performing Test HAVE_C_MSSE - Success
  -- Performing Test HAVE_CXX_MSSE2
  -- Performing Test HAVE_CXX_MSSE2 - Success
  -- Performing Test HAVE_C_MSSE2
  -- Performing Test HAVE_C_MSSE2 - Success
  -- Performing Test HAVE_CXX_MSSE3
  -- Performing Test HAVE_CXX_MSSE3 - Success
  -- Performing Test HAVE_C_MSSE3
  -- Performing Test HAVE_C_MSSE3 - Success
  -- Performing Test HAVE_CXX_FFUNCTION_SECTIONS
  -- Performing Test HAVE_CXX_FFUNCTION_SECTIONS - Success
  -- Performing Test HAVE_C_FFUNCTION_SECTIONS
  -- Performing Test HAVE_C_FFUNCTION_SECTIONS - Success
  -- Performing Test HAVE_CXX_FVISIBILITY_HIDDEN
  -- Performing Test HAVE_CXX_FVISIBILITY_HIDDEN - Success
  -- Performing Test HAVE_C_FVISIBILITY_HIDDEN
  -- Performing Test HAVE_C_FVISIBILITY_HIDDEN - Success
  -- Performing Test HAVE_CXX_FVISIBILITY_INLINES_HIDDEN
  -- Performing Test HAVE_CXX_FVISIBILITY_INLINES_HIDDEN - Success
  -- Performing Test HAVE_C_FVISIBILITY_INLINES_HIDDEN
  -- Performing Test HAVE_C_FVISIBILITY_INLINES_HIDDEN - Failed
  -- Looking for pthread.h
  -- Looking for pthread.h - found
  -- Found ZLIB: /usr/local/lib/libz.so (found suitable version "1.2.8",   minimum required is "1.2.3") 
  -- Found TIFF: /usr/lib/x86_64-linux-gnu/libtiff.so (found version "4.0.3") 
  -- Found JPEG: /usr/lib/x86_64-linux-gnu/libjpeg.so  
  -- Found WebP: /usr/lib/x86_64-linux-gnu/libwebp.so  
  -- Found Jasper: /usr/lib/x86_64-linux-gnu/libjasper.so (found version "1.900.1") 
  -- Found ZLIB: /usr/local/lib/libz.so (found version "1.2.8") 
  -- Found PNG: /usr/lib/x86_64-linux-gnu/libpng.so (found version "1.2.50") 
  -- Looking for /usr/include/libpng/png.h
  -- Looking for /usr/include/libpng/png.h - found
  -- Found OpenEXR: /usr/lib/x86_64-linux-gnu/libIlmImf.so
  -- checking for module 'gtk+-2.0'
  --   found gtk+-2.0, version 2.24.23
  -- checking for module 'gthread-2.0'
  --   found gthread-2.0, version 2.42.2
  -- checking for module 'gstreamer-base-0.10'
  --   found gstreamer-base-0.10, version 0.10.36
  -- checking for module 'gstreamer-video-0.10'
  --   found gstreamer-video-0.10, version 0.10.36
  -- checking for module 'gstreamer-app-0.10'
  --   found gstreamer-app-0.10, version 0.10.36
  -- checking for module 'gstreamer-riff-0.10'  
  --   found gstreamer-riff-0.10, version 0.10.36
  -- checking for module 'gstreamer-pbutils-0.10'
  --   found gstreamer-pbutils-0.10, version 0.10.36
  -- checking for module 'libdc1394-2'
  --   found libdc1394-2, version 2.2.1
  -- checking for module 'libv4l1'
  --   found libv4l1, version 1.0.1
  -- Looking for linux/videodev.h
  -- Looking for linux/videodev.h - not found
  -- Looking for linux/videodev2.h
  -- Looking for linux/videodev2.h - found
  -- Looking for sys/videoio.h
  -- Looking for sys/videoio.h - not found
  -- checking for module 'libavcodec'
  --   found libavcodec, version 54.35.0
  -- checking for module 'libavformat'
  --   found libavformat, version 54.20.4
  -- checking for module 'libavutil'
  --   found libavutil, version 52.3.0
  -- checking for module 'libswscale'
  --   found libswscale, version 2.1.1
  -- Looking for libavformat/avformat.h
  -- Looking for libavformat/avformat.h - found
  -- Looking for ffmpeg/avformat.h
  -- Looking for ffmpeg/avformat.h - not found
  -- Found PythonInterp: /usr/bin/python2.7 (found suitable version "2.7.6", minimum required is "2.7") 
  -- Found PythonLibs: /usr/lib/x86_64-linux-gnu/libpython2.7.so (found suitable exact version "2.7.6") 
  -- Found JNI: /usr/lib/jvm/default-java/jre/lib/amd64/libjawt.so  
  -- Could NOT find Matlab (missing:  MATLAB_MEX_SCRIPT MATLAB_INCLUDE_DIRS MATLAB_ROOT_DIR MATLAB_LIBRARIES MATLAB_LIBRARY_DIRS MATLAB_MEXEXT  MATLAB_ARCH MATLAB_BIN) 
  -- Performing Test HAVE_CXX_WNO_UNDEF
  -- Performing Test HAVE_CXX_WNO_UNDEF - Success
  -- Performing Test HAVE_CXX_WNO_MISSING_DECLARATIONS
  -- Performing Test HAVE_CXX_WNO_MISSING_DECLARATIONS - Success
  -- Performing Test HAVE_CXX_WNO_SHADOW
  -- Performing Test HAVE_CXX_WNO_SHADOW - Success
  -- Performing Test HAVE_CXX_WNO_UNUSED_PARAMETER
  -- Performing Test HAVE_CXX_WNO_UNUSED_PARAMETER - Success
  -- Performing Test HAVE_CXX_WNO_MISSING_PROTOTYPES
  -- Performing Test HAVE_CXX_WNO_MISSING_PROTOTYPES - Failed
  -- Performing Test HAVE_CXX_WNO_DEPRECATED_DECLARATIONS
  -- Performing Test HAVE_CXX_WNO_DEPRECATED_DECLARATIONS - Success
  -- 
  -- General configuration for OpenCV 3.0.0-dev  =====================================
  --   Version control:               2.4.7-2265-g95006af
  -- 
  --   Platform:
  --     Host:                        Linux 3.13.0-55-generic x86_64
  --     CMake:                       2.8.12.2
  --     CMake generator:             Unix Makefiles
  --     CMake build tool:            /usr/bin/make
  --     Configuration:               Release
  -- 
  --   C/C++:
  --     Built as dynamic libs?:      YES
  --     C++ Compiler:                /usr/bin/g++  (ver 4.9.2)
  --     C++ flags (Release):         -fsigned-char -W -Wall  -Werror=return-type -Werror=non-virtual-dtor -Werror=address  -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG  -DNDEBUG
  --     C++ flags (Debug):           -fsigned-char -W -Wall   -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG -ggdb3
  --     C Compiler:                  /usr/bin/cc
  --     C flags (Release):           -fsigned-char -W -Wall  -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -fvisibility=hidden -O3 -DNDEBUG  -DNDEBUG
  --     C flags (Debug):             -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG -ggdb3
  --     Linker flags (Release):      
  --     Linker flags (Debug):        
  --     Precompiled headers:         YES
  -- 
  --   OpenCV modules:
  --     To be built:                 core flann imgproc highgui features2d calib3d ml objdetect video ocl bioinspired cudaarithm nonfree contrib cudawarping cuda cudafilters cudaimgproc legacy cudabgsegm cudacodec cudafeatures2d cudaoptflow cudastereo optim photo softcascade python shape stitching superres ts videostab
  --     Disabled:                    viz world
  --     Disabled by dependency:      -
  --     Unavailable:                 androidcamera cudalegacy cudev java matlab
  -- 
  --   GUI: 
  --     QT:                          NO
  --     GTK+ 2.x:                    YES (ver 2.24.23)
  --     GThread :                    YES (ver 2.42.2)
  --     GtkGlExt:                    NO
  --     OpenGL support:              NO
  -- 
  --   Media I/O: 
  --     ZLib:                        /usr/local/lib/libz.so (ver 1.2.8)
  --     JPEG:                        /usr/lib/x86_64-linux-gnu/libjpeg.so (ver )
  --     WEBP:                        /usr/lib/x86_64-linux-gnu/libwebp.so (ver encoder: 0x0202)
  --     PNG:                         /usr/lib/x86_64-linux-gnu/libpng.so (ver 1.2.50)
  --     TIFF:                        /usr/lib/x86_64-linux-gnu/libtiff.so (ver 42 - 4.0.3)
  --     JPEG 2000:                   /usr/lib/x86_64-linux-gnu/libjasper.so (ver 1.900.1)
  --     OpenEXR:                     /usr/lib/x86_64-linux-gnu/libImath.so /usr/lib/x86_64-linux-gnu/libIlmImf.so /usr/lib/x86_64-linux-gnu/libIex.so /usr/lib/x86_64-linux-gnu/libHalf.so /usr/lib/x86_64-linux-gnu/libIlmThread.so (ver 1.6.1)
  -- 
  --   Video I/O:
  --     DC1394 1.x:                  NO
  --     DC1394 2.x:                  YES (ver 2.2.1)
  --     FFMPEG:                      YES
  --       codec:                     YES (ver 54.35.0)
  --       format:                    YES (ver 54.20.4)
  --       util:                      YES (ver 52.3.0)
  --       swscale:                   YES (ver 2.1.1)
  --       gentoo-style:              YES
  --     GStreamer:                   
  --       base:                      YES (ver 0.10.36)
  --       video:                     YES (ver 0.10.36)
  --       app:                       YES (ver 0.10.36)
  --       riff:                      YES (ver 0.10.36)
  --       pbutils:                   YES (ver 0.10.36)
  --     OpenNI:                      NO
  --     OpenNI PrimeSensor Modules:  NO
  --     PvAPI:                       NO
  --     GigEVisionSDK:               NO
  --     UniCap:                      NO
  --     UniCap ucil:                 NO
  --     V4L/V4L2:                    Using libv4l (ver 1.0.1)
  --     XIMEA:                       NO
  --     Xine:                        NO
  -- 
  --   Other third-party libraries:
  --     Use IPP:                     NO
  --     Use Eigen:                   YES (ver 3.2.4)
  --     Use TBB:                     NO
  --     Use OpenMP:                  NO
  --     Use GCD                      NO
  --     Use Concurrency              NO
  --     Use C=:                      NO
  --     Use Cuda:                    NO
  --     Use OpenCL:                  YES
  -- 
  --   OpenCL:
  --     Version:                     dynamic
  --     Include path:                /home/r/Desktop/opecv/opencv/3rdparty/include/opencl/1.2
  --     Use AMDFFT:                  NO
  --     Use AMDBLAS:                 NO
  -- 
  --   Python:
  --     Interpreter:                 /usr/bin/python2.7 (ver 2.7.6)
  --     Libraries:                   /usr/lib/x86_64-linux-gnu/libpython2.7.so (ver 2.7.6)
  --     numpy:                       /usr/lib/python2.7/dist-packages/numpy/core/include (ver 1.8.2)
  --     packages path:               lib/python2.7/dist-packages
  -- 
  --   Java:
  --     ant:                         NO
  --     JNI:                         /usr/lib/jvm/default-java/include /usr/lib/jvm/default-java/include /usr/lib/jvm/default-java/include
  --     Java tests:                  NO
  -- 
  --   Matlab:
  --     mex:                         NO
  -- 
  --   Documentation:
  --     Build Documentation:         NO
  --     Sphinx:                      NO
  --     PdfLaTeX compiler:           /usr/bin/pdflatex
  --     PlantUML:                    NO
  -- 
  --   Tests and samples:
  --     Tests:                       YES
  --     Performance tests:           YES
  --     C/C++ Examples:              NO
  -- 
  --   Install path:                  /usr/local
  -- 
  --   cvconfig.h is in:              /home/r/Desktop/opecv/opencv
  -- -----------------------------------------------------------------
  -- 
  CMake Warning at CMakeLists.txt:943 (message):
  The source directory is the same as binary directory.  "make clean" may
  damage the source tree
  
  
  -- Configuring done
  -- Generating done
  -- Build files have been written to: /home/r/Desktop/opecv/opencv
  </code></pre>