Re: [Caffe / ITP / FTBFS] undefined reference to `XXX` issue

[Julien Puydt <julien.puydt@laposte.net>]

Hi,

Le samedi 03 oct. 2015 à 03:28:31 (+0000), lumin a écrit :
> ```
> /usr/include/glog/logging.h:672: undefined reference to `google::base::CheckOpMessageBuilder::NewString()'
> CMakeFiles/caffe.bin.dir/caffe.cpp.o: In function `std::string* google::MakeCheckOpString<float, int>(float const&, int const&, char const*)':
> /usr/include/glog/logging.h:672: undefined reference to `google::base::CheckOpMessageBuilder::NewString()'
> ../lib/libcaffe.so.0: undefined reference to `google::protobuf::Message::InitializationErrorString() const'
> ../lib/libcaffe.so.0: undefined reference to `google::protobuf::internal::WireFormatLite::WriteStringMaybeAliased(int, std::string const&, google::protobuf::io::CodedOutputStream*)'
> ../lib/libcaffe.so.0: undefined reference to `google::protobuf::io::CodedOutputStream::WriteStringWithSizeToArray(std::string const&, unsigned char*)'
> ```

Many undefined references, in various libraries. And most seem to mention
*strings*.

> And here are some notable points:
> 
> 1. I'm doing linking with gcc/g++ 4.9 on libXXXv5 libraries.
>    However when my caffe-cuda build succeed on testing machine (gcc-4.9 + CUDA 6.5),
>    gcc is linking ELFs against libXXX rather than libXXXv5.
>    I don't know if gcc-5 libs is root of trouble.

It does look a promising explanation:
https://wiki.debian.org/GCC5
(especially since they insist std::string is a big trouble-maker!)

My suggestion is: call for help on debian-gcc's mailing-list!

Snark on #debian-science