Undefined symbols for architecture armv7 on integrating OpenCV framework

Question

I am facing this error, when integrating opencv2.framework, can any one help this out. My Xcode version is 4.5.

Undefined symbols for architecture armv7:
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::basic_string(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      cv::Exception::Exception(int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int) in opencv2(system.o)
      cv::Exception::Exception(cv::Exception const&) in opencv2(system.o)
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()", referenced from:
      cv::Mat::create(int, int const*, int) in opencv2(matrix.o)
      __ZN2cvL7setSizeERNS_3MatEiPKiPKmb in opencv2(matrix.o)
      cv::Mat::Mat(cv::Mat const&, cv::Range const&, cv::Range const&) in opencv2(matrix.o)
      cv::Mat::Mat(cv::Mat const&, cv::Range const*) in opencv2(matrix.o)
      cv::Mat::diag(int) const in opencv2(matrix.o)
      cv::Mat::Mat(_IplImage const*, bool) in opencv2(matrix.o)
      cv::Mat::reserve(unsigned long) in opencv2(matrix.o)
      ...
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned long)", referenced from:
      cv::Mat::create(int, int const*, int) in opencv2(matrix.o)
      __ZN2cvL7setSizeERNS_3MatEiPKiPKmb in opencv2(matrix.o)
      cv::Mat::Mat(cv::Mat const&, cv::Range const&, cv::Range const&) in opencv2(matrix.o)
      cv::Mat::Mat(cv::Mat const&, cv::Range const*) in opencv2(matrix.o)
      cv::Mat::diag(int) const in opencv2(matrix.o)
      cv::Mat::Mat(_IplImage const*, bool) in opencv2(matrix.o)
      cv::Mat::reserve(unsigned long) in opencv2(matrix.o)
      ...
  "std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
      std::__1::vector<cv::Vec<int, 128>, std::__1::allocator<cv::Vec<int, 128> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 64>, std::__1::allocator<cv::Vec<int, 64> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 32>, std::__1::allocator<cv::Vec<int, 32> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 16>, std::__1::allocator<cv::Vec<int, 16> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 12>, std::__1::allocator<cv::Vec<int, 12> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 9>, std::__1::allocator<cv::Vec<int, 9> > >::__append(unsigned long) in opencv2(matrix.o)
      std::__1::vector<cv::Vec<int, 8>, std::__1::allocator<cv::Vec<int, 8> > >::__append(unsigned long) in opencv2(matrix.o)
      ...
  "std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::operator=(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      cv::Exception::formatMessage() in opencv2(system.o)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

You only need to add "libc++.dylib" into your "Linked Frameworks and Libraries"

Answer 2

It appears the framework is not compiled to support arm7. It needs to be compiled using the current Xcode so that it can target the necessary architectures.

Are you compiling from source or relying on an existing binary?

Try using this Git repository for source: https://github.com/jonmarimba/OpenCV-iOS