尝试从 makefile 构建 assimp 时出现多个 -fpermissive 错误

问：

我已经使用 git 下载了 assimp 源代码。然后我使用了 cmake，但我必须添加标志 - 为了回避一些早期的编译问题，在这些问题上，我收到有关 stb_i.h 中函数被定义但未使用的错误。当我键入时，我收到以下编译错误git clone https://github.com/assimp/assimp.gitDASSIMP_WARNINGS_AS_ERRORS=OFFsudo make

/home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.cpp:226:13: error: specialization of ‘template<class _Tp> struct std::hash’ in different namespace [-fpermissive]
 struct std::hash<Vertex> {
             ^
In file included from /usr/include/c++/5/bits/basic_string.h:5471:0,
                 from /usr/include/c++/5/string:52,
                 from /usr/include/c++/5/bits/locale_classes.h:40,
                 from /usr/include/c++/5/bits/ios_base.h:41,
                 from /usr/include/c++/5/ios:42,
                 from /usr/include/c++/5/ostream:38,
                 from /usr/include/c++/5/iterator:64,
                 from /home/kshaugnnessy/Downloads/engine/assimp/contrib/utf8cpp/source/utf8/core.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/contrib/utf8cpp/source/utf8/checked.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/../contrib/utf8cpp/source/utf8.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/types.h:79,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/Importer.hpp:60,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/GenericProperty.h:52,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/Common/BaseProcess.h:46,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.h:48,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.cpp:48:
/usr/include/c++/5/bits/functional_hash.h:58:12: error:   from definition of ‘template<class _Tp> struct std::hash’ [-fpermissive]
     struct hash;
            ^
/home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.cpp:235:13: error: specialization of ‘template<class _Tp> struct std::equal_to’ in different namespace [-fpermissive]
 struct std::equal_to<Vertex> {
             ^
In file included from /usr/include/c++/5/string:48:0,
                 from /usr/include/c++/5/bits/locale_classes.h:40,
                 from /usr/include/c++/5/bits/ios_base.h:41,
                 from /usr/include/c++/5/ios:42,
                 from /usr/include/c++/5/ostream:38,
                 from /usr/include/c++/5/iterator:64,
                 from /home/kshaugnnessy/Downloads/engine/assimp/contrib/utf8cpp/source/utf8/core.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/contrib/utf8cpp/source/utf8/checked.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/../contrib/utf8cpp/source/utf8.h:31,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/types.h:79,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/Importer.hpp:60,
                 from /home/kshaugnnessy/Downloads/engine/assimp/include/assimp/GenericProperty.h:52,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/Common/BaseProcess.h:46,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.h:48,
                 from /home/kshaugnnessy/Downloads/engine/assimp/code/PostProcessing/JoinVerticesProcess.cpp:48:
/usr/include/c++/5/bits/stl_function.h:332:12: error:   from definition of ‘template<class _Tp> struct std::equal_to’ [-fpermissive]
     struct equal_to;
            ^
code/CMakeFiles/assimp.dir/build.make:747: recipe for target 'code/CMakeFiles/assimp.dir/PostProcessing/JoinVerticesProcess.cpp.o' failed
make[2]: *** [code/CMakeFiles/assimp.dir/PostProcessing/JoinVerticesProcess.cpp.o] Error 1
CMakeFiles/Makefile2:203: recipe for target 'code/CMakeFiles/assimp.dir/all' failed
make[1]: *** [code/CMakeFiles/assimp.dir/all] Error 2
Makefile:135: recipe for target 'all' failed
make: *** [all] Error 2

我能做些什么来使它工作？

谢谢。