OpenCV Linux 安装 Make出错

执行完CMake之后再执行make时遇到以下错误

 [  %] Generating precomp.hpp.gch/opencv_core_Release.gch
 In file included from /usr/include/c++//bits/stl_algo.h::,
                  from /usr/include/c++//algorithm:,
                  from /opt/opencv/opencv-3.1./modules/core/include/opencv2/core/base.hpp:,
                  from /opt/opencv/opencv-3.1./modules/core/include/opencv2/core.hpp:,
                  from /opt/opencv/opencv-3.1./modules/core/include/opencv2/core/utility.hpp:,
                  from /opt/opencv/build/modules/core/precomp.hpp::
 /usr/include/c++//cstdlib::: fatal error: stdlib.h: 没有那个文件或目录
  #include_next <stdlib.h>
                          ^
 compilation terminated.
 modules/core/CMakeFiles/pch_Generate_opencv_core.dir/build.make:: recipe for target 'modules/core/precomp.hpp.gch/opencv_core_Release.gch' failed
 make[]: *** [modules/core/precomp.hpp.gch/opencv_core_Release.gch] Error
 CMakeFiles/Makefile2:: recipe for target 'modules/core/CMakeFiles/pch_Generate_opencv_core.dir/all' failed
 make[]: *** [modules/core/CMakeFiles/pch_Generate_opencv_core.dir/all] Error
 Makefile:: recipe for target 'all' failed
 make: *** [all] Error 

这是由于gcc6已经吧stdlib.h纳入了libstdc++以进行更好的优化，C Library的头文件stdlib.h使用 Include_next，而include_next对gcc系统头文件路径很敏感。

推荐的修复方法是不要把include路径作为系统目录，而是使用标准方式包含include 目录

翻译自 https://bugs.webkit.org/show_bug.cgi?id=161697

原文说明：

Trying to build WebKitGTK+ with GCC  I got this error:

In file included from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/sysroots/qemux86/usr/include/c++/6.2./ext/string_conversions.h::,
                 from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/sysroots/qemux86/usr/include/c++/6.2./bits/basic_string.h:,
                 from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/sysroots/qemux86/usr/include/c++/6.2./string:,
                 from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/work/i586-oe-linux/webkitgtk/2.12.-r0/webkitgtk-2.12./Source/ThirdParty/ANGLE/src/common/debug.h:,
                 from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/work/i586-oe-linux/webkitgtk/2.12.-r0/webkitgtk-2.12./Source/ThirdParty/ANGLE/src/common/mathutil.h:,
                 from /home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/work/i586-oe-linux/webkitgtk/2.12.-r0/webkitgtk-2.12./Source/ThirdParty/ANGLE/src/common/mathutil.cpp::
/home/igalia/clopez/yocto/commit-builds/meta-webkit/builds/qemux86-/tmp-glibc/sysroots/qemux86/usr/include/c++/6.2./cstdlib::: fatal error: stdlib.h: No such file or directory
 #include_next <stdlib.h>

The issue seems to be that GCC  has now introduced stdlib.h in libstdc++ for better compliance and its including the C library stdlib.h using include_next which is sensitive to order of system header include paths. See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70129

The recommended way to fix this is to stop adding include directories as system ones (-isystem) and instead use the standard way to include directories (-I)

The openembedded project is carrying this downstream patch against WebKitGTK+ 2.12 with the above fix: http://git.openembedded.org/openembedded-core/tree/meta/recipes-sato/webkit/files/0001-WebKitMacros-Append-to-I-and-not-to-isystem.patch

OpenCV对gcc6支持不完善，导致gcc不兼容OpenCV

解决方法：卸载Ubuntu 16，使用Ubuntu 14

===========================================================

以上解法其实没有必要，gcc6并不是不能编译OpenCV 3，加入以下编译选项即可

-DENABLE_PRECOMPILED_HEADERS=OFF

知识来源：https://www.cnblogs.com/wuchaodzxx/p/8418980.html

感谢提供解法。