CMake Warning at source_subfolder/cmake/OpenCVDetectPython.cmake:81 (message): CMake's 'find_host_package(PythonInterp 2.7)' found wrong Python version: PYTHON_EXECUTABLE=/opt/pyenv/versions/3.7.5/bin/python PYTHON_VERSION_STRING=3.7.5 Consider providing the 'PYTHON2_EXECUTABLE' variable via CMake command line or environment variables Call Stack (most recent call first): source_subfolder/cmake/OpenCVDetectPython.cmake:271 (find_python) source_subfolder/CMakeLists.txt:606 (include) Traceback (most recent call last): File "", line 1, in ModuleNotFoundError: No module named 'numpy' In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/loadsave.cpp:47: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmts.hpp:53: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmt_exr.hpp:52: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfChromaticities.h:46: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImathVec.h:46: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImathExc.h:47: /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/IexBaseExc.h:68:41: error: use of undeclared identifier 'nullptr' IEX_EXPORT BaseExc (const char *s = nullptr) throw(); // std::string (s) ^ In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/loadsave.cpp:47: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmts.hpp:53: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmt_exr.hpp:53: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfInputFile.h:47: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfFrameBuffer.h:55: In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/7.2.0/../../../../include/c++/7.2.0/cstdint:35: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.2.0/../../../../include/c++/7.2.0/bits/c++0x_warning.h:32:2: error: This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options. #error This file requires compiler and library support \ ^ In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/loadsave.cpp:47: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmts.hpp:53: In file included from /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/source_subfolder/modules/imgcodecs/src/grfmt_exr.hpp:53: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfInputFile.h:48: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfTiledOutputFile.h:50: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfGenericOutputFile.h:40: In file included from /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/ImfXdr.h:108: /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/half.h:104:19: error: expected ';' at end of declaration list half (half &&) noexcept = default; ^ /home/conan/w/cci_PR-3465/.conan/data/openexr/2.5.2/_/_/package/85c0b370fd0e49d21f07fa09e5b9179a3f11961a/include/OpenEXR/half.h:125:35: error: expected ';' at end of declaration list half & operator = (half &&h) noexcept = default; ^ 4 errors generated. make[2]: *** [source_subfolder/modules/imgcodecs/CMakeFiles/opencv_imgcodecs.dir/src/loadsave.cpp.o] Error 1 make[1]: *** [source_subfolder/modules/imgcodecs/CMakeFiles/opencv_imgcodecs.dir/all] Error 2 make[1]: *** Waiting for unfinished jobs.... make: *** [all] Error 2 opencv/3.4.12: WARN: Build folder is dirty, removing it: /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7 opencv/3.4.12: ERROR: Package 'a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7' build failed opencv/3.4.12: WARN: Build folder /home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7 ERROR: opencv/3.4.12: Error in build() method, line 192 cmake.build() ConanException: Error 2 while executing cmake --build '/home/conan/w/cci_PR-3465/.conan/data/opencv/3.4.12/_/_/build/a7749dff2dbdb1cc7b577bdcabda84e7bdd89ea7/build_subfolder' '--' '-j3'