Undefined reference to c10::Error::Error

C++
1

I’m trying to compile a minimal C++ torch test program. This is the code:

#include <torch/torch.h>

#include <iostream>

int main()
{
    torch::Tensor tensor = torch::rand({2,3});
    std::clog << tensor << std::endl;
}

The CMake files provided with source code don’t work well with my project, so I wrote a simple CMake. Nevertheless, the final command line to linker is:

/home/yangxi/software/clang+llvm-5.0.1-x86_64-linux-gnu-debian8/bin/clang++  -g  -rdynamic CMakeFiles/test1.dir/test1.cpp.o  -o test1 -Wl,-rpath,/home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libtorch.so sibling/treecore/src/libtreecore_dbg.a /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libcudart-1581fefa.so.10.0 /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libgomp-4f651535.so.1 /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libnvToolsExt-3965bdd0.so.1 /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libc10_cuda.so /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libc10.so -lpthread -ldl sibling/treecore/sibling/3rd_party/zlib/libzlib_static.a

It claims many linker errors about c10::Error constructor unresolved:

CMakeFiles/test1.dir/test1.cpp.o: In function `c10::backendToDeviceType(c10::Backend)':
/home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/include/c10/core/Backend.h:169: undefined reference to `c10::Error::Error(c10::SourceLocation, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/include/c10/core/Backend.h:171: undefined reference to `c10::Error::Error(c10::SourceLocation, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
......
......

However, I can see the constructor by objdump -C -d /home/yangxi/projects/TBTNativeCodingMegaProject/3rd_party/Torch/1.2.0/linux/lib/libc10.so, it is just there:

0000000000012ab0 <c10::Error::Error(c10::SourceLocation, std::string const&)@plt>:
   12ab0:       ff 25 ea 55 23 00       jmpq   *0x2355ea(%rip)        # 2480a0 <c10::Error::Error(c10::SourceLocation, std::string const&)@@Base+0x218080>
   12ab6:       68 11 00 00 00          pushq  $0x11
   12abb:       e9 d0 fe ff ff          jmpq   12990 <.plt>

So I have no idea on how to solve the symbol…

2

Your compiler expects cxx11 ABI symbol std::__cxx11::basic_string. We now have new ABI binaries for libtorch and they can be found on http://pytorch.org, or at https://github.com/pytorch/pytorch/issues/17492#issuecomment-524692441.

Alternatively, you can use your compiler to compile libtorch from scratch using instructions at https://github.com/pytorch/pytorch/blob/master/docs/libtorch.rst.

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