Could not build "Linking error"

[marwanhazemblnk]

Launching lib/main.dart on CPH2159 in debug mode... Running Gradle task 'assembleDebug'...

FAILURE: Build failed with an exception.

• What went wrong: Execution failed for task ':native_with_opencv:externalNativeBuildDebug'.

Build command failed. Error while executing process /Users/marwanhazem/Library/Android/sdk/cmake/3.6.4111459/bin/cmake with arguments {--build /Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/android/.cxx/cmake/debug/armeabi-v7a --target native_with_opencv} [1/2] Building CXX object CMakeFiles/native_with_opencv.dir/Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/ios/Classes/native_add.cpp.o [2/2] Linking CXX shared library /Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/example/build/native_with_opencv/intermediates/cmake/debug/obj/armeabi-v7a/libnative_with_opencv.so FAILED: : && /Users/marwanhazem/Library/Android/sdk/ndk/21.1.6352462/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ --target=armv7-none-linux-androideabi21 --gcc-toolchain=/Users/marwanhazem/Library/Android/sdk/ndk/21.1.6352462/toolchains/llvm/prebuilt/darwin-x86_64 --sysroot=/Users/marwanhazem/Library/Android/sdk/ndk/21.1.6352462/toolchains/llvm/prebuilt/darwin-x86_64/sysroot -fPIC -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -D_FORTIFY_SOURCE=2 -march=armv7-a -mthumb -Wformat -Werror=format-security -frtti -fexceptions -std=c++11 -O0 -fno-limit-debug-info -Wl,--exclude-libs,libgcc.a -Wl,--exclude-libs,libgcc_real.a -Wl,--exclude-libs,libatomic.a -static-libstdc++ -Wl,--build-id -Wl,--fatal-warnings -Wl,--exclude-libs,libunwind.a -Wl,--no-undefined -Qunused-arguments -shared -Wl,-soname,libnative_with_opencv.so -o /Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/example/build/native_with_opencv/intermediates/cmake/debug/obj/armeabi-v7a/libnative_with_opencv.so CMakeFiles/native_with_opencv.dir/Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/ios/Classes/native_add.cpp.o -llog /Users/marwanhazem/Downloads/OpenCV-android-sdk/sdk/native/staticlibs/armeabi-v7a/libopencv_core.a /Users/marwanhazem/Downloads/OpenCV-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libtbb.a libcpufeatures.a /Users/marwanhazem/Downloads/OpenCV-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libittnotify.a /Users/marwanhazem/Downloads/OpenCV-android-sdk/sdk/native/3rdparty/libs/armeabi-v7a/libtegra_hal.a -lz -ldl -latomic -lm && : /Users/marwanhazem/Downloads/flutter_cpp_with_opencv-master/ios/Classes/native_add.cpp:15: error: undefined reference to 'cv::getPerspectiveTransform(cv::_InputArray const&, cv::_InputArray const&, int)' clang++: error: linker command failed with exit code 1 (use -v to see invocation) ninja: build stopped: subcommand failed.

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BUILD FAILED in 5s Exception: Gradle task assembleDebug failed with exit code 1