Question

I’m still quite new to Objective C and Xcode, but I just finished a small app that uses the openCV libopencv_core.2.4.2.dylib.

When I went to open the final built app on another machine, OS X threw me this error:

Dyld Error Message:   Library not loaded: */libopencv_core.2.4.dylib  
Referenced from: /Users/USER/Desktop/my
app.app/Contents/MacOS/my app   
Reason: image not found

Why is my app looking for 2.4 instead of 2.4.2 here?

What I already checked:

I added a new build phase -> so that libopencv_core.2.4.2.dylib is copied to the app package (via “Copy Bundle Resources” in Xcode) – libopencv_core.2.4.2.dylib now lies in my app.app/Resources

What did I miss? Do I have so set some more library search paths or similar?

What I also did:

install_name_tool -id "@executable_path/../Frameworks/libopencv_core.2.4.2.dylib" libopencv_core.2.4.2.dylib

Copying the dylib to the Frameworks directory doesn’t work either:

Library not loaded: @executable_path/../Frameworks/libopencv_core.2.4.2.dylib

Don’t know what to do now – the dylib is in the Frameworks directory of my app…

Using otool -L on the binary gives me:

/System/Library/Frameworks/Cocoa.framework/Versions/A/Cocoa (compatibility version 1.0.0, current version 19.0.0)
    @loader_path/../Frameworks/libopencv_core.2.4.2.dylib (compatibility version 2.4.0, current version 2.4.2)
    @loader_path/../Frameworks/libopencv_highgui.2.4.2.dylib (compatibility version 2.4.0, current version 2.4.2)
    @loader_path/../Frameworks/libopencv_imgproc.2.4.2.dylib (compatibility version 2.4.0, current version 2.4.2)
    /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation (compatibility version 300.0.0, current version 945.11.0)
    /usr/lib/libobjc.A.dylib (compatibility version 1.0.0, current version 228.0.0)
    /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 56.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 169.3.0)
    /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 744.1.0)
    /System/Library/Frameworks/CoreData.framework/Versions/A/CoreData (compatibility version 1.0.0, current version 407.7.0)
    /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit (compatibility version 45.0.0, current version 1187.33.0)

Answer 1

I found a better solution: recompiling openCV in Xcode and set the @executable_path/../Frameworks in the build settings, for every .dylib you compile – now the .dylibs themselves always “know where they are”.