CODEWITHSUNDEEP
c++macosopencvshared-librariesdyld
coldmoon
coldmoon

Reputation: 33

dyld: Symbol not found: __ZN2cv6imreadERKNSt3 when run a simple code on MAC OS 10.10

I'm trying to run the following code on MAC OS 10.10:

#include <cv.h>    
#include <highgui.h>    

using namespace std;
using namespace cv;

int main() 
{
    Mat img = imread("xxx.jpg");
    imshow("image", img);
    waitKey(0);

    return 0;
}

This code can be built successfully. But, when I run it, I always get the error message:

dyld: lazy symbol binding failed: Symbol not found: 
__ZN2cv6imreadERKNSt3__112basic_stringIcNS0_11char_traitsIcEENS0_9allocatorIcEEEEi
Referenced from:    
/Users/Coldmoon/ComputerVisionApps/opencvTest/Build/Products/Debug/opencvTest
Expected in: /usr/local/lib/libopencv_highgui.2.4.dylib

I have two different versions of opencv. One is built with libstdc++, the other is built with libc++. Both are opencv 2.4.9. I want to build the above code using libc++ opencv.

So, in the Xcode 6.1, I set Header Search Path and Library Search Path to point to libc++ opencv which is in /Users/Coldmoon/MyLibraries/opencv-2.4.9 and set C++ Standard Library to libc++.

My question: It seems that compiler does not link the libc++ opencv but libstdc++ opencv instead which is in /usr/local/lib.

I'm totally confused. Is there anything I miss?

Upvotes: 1

Views: 3095

Answers (1)

Paul
Paul

Reputation: 13238

Library Search Paths tells linker where to search for the library to link to. But when the executable is run, the library may be searched by dynamic loader (dyld) in different places. This is controlled by 'Install Name' of the library that may be queried by otool -D libFoo.dylib.

So, for example, if the library you are linking to is in /bar/libFoo.dylib, but its install name is /baz/libFoo.dylib, you need to put /bar in Library Search Paths, but when you run the binary it'll be searched in /baz.

You can also find out where the libraries are seachred when the executable is run by otool -L <executable>.

If the path to shared library is not absolute, dynamic loader tries to load it from some standard paths. If you set DYLD_PRINT_LIBRARIES environment variable, dyld will log the filenames of the libraries it tries to load to stderr. You can override the paths where dyld searches for libraries by setting DYLD_LIBRARY_PATH variable (:-separated list of paths).

More info about dyld environment variables can be found in man dyld.

Upvotes: 4

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