# Issues with graphic/opencv



## vertexSymphony (Jul 3, 2011)

Hi!

I'm posting because I've recently had some issues with graphics/opencv. Here's the relevant part of the build log:


```
[ 75%] Building C object samples/c/CMakeFiles/example_convert_cascade.dir/convert_cascade.o
Linking C executable ../../bin/contours
Linking C executable ../../bin/convert_cascade
../../lib/libopencv_calib3d.so.2.3.0: undefined reference to `std::_List_node_base::_M_hook(std::_List_node_base*)@GLIBCXX_3.4.14'
../../lib/libopencv_calib3d.so.2.3.0: undefined reference to `std::_List_node_base::_M_hook(std::_List_node_base*)@GLIBCXX_3.4.14'
../../lib/libopencv_calib3d.so.2.3.0: undefined reference to `std::_List_node_base::_M_transfer(std::_List_node_base*, std::_List_node_base*)@GLIBCXX_3.4.14'
../../lib/libopencv_features2d.so.2.3.0: undefined reference to `std::ctype<char>::_M_widen_init() const@GLIBCXX_3.4.11'
../../lib/libopencv_calib3d.so.2.3.0: undefined reference to `std::_List_node_base::_M_transfer(std::_List_node_base*, std::_List_node_base*)@GLIBCXX_3.4.14'
../../lib/libopencv_features2d.so.2.3.0: undefined reference to `std::ctype<char>::_M_widen_init() const@GLIBCXX_3.4.11'
collect2: ld returned 1 exit status
collect2: ld returned 1 exit status
```

I've noticed that the problem were the examples, so I went to the work"directory and turned them off and upgraded just peacefully.
I have to say (and I think is relevant) that I'm using lang/gcc45 for basically every port (except a few).

So this raises two questions:
Are graphics/opencv examples needed?
If not ... can that be changed to an option in config to disable them? (I've later noticed NOPORTEXAMPLES in the Makefile, but IMHO it should be promoted to an option).

Thanks for reading!
Alex.


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## wblock@ (Jul 3, 2011)

Adding an EXAMPLES option looks like an easy patch.  Whether it's an option or not, the port should still build.  My suggestion would be to make the patch and include it in an email to the maintainer about the problem.


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