Segmentation fault (core dumped) during loading shared library in Python ctypes

Question

I am trying to load C shared library in Python ctypes. (linux)

But It makes a Segmentation fault (core dumped) during loading the shared library.

That means (if the name of library is A.so )

import ctypes

ctyps.CDLL("A.so")   #it makes Segmentation fault

What I want to know is usually what is a problem if Segmentation fault happens during loading the library.

I don't understand it is compiled normally and I don't any call to functions in the library.

Which part lead this error during loading the library?

Answer 1

In my case, that was template type problem in C++ side. For example, I defined a class with template like below.

# a.hpp
template<typename msgType>
class A{
public:
int get(msgType& msg);
...
...
};


#a.cpp
template<typename msgType>
int A<msgType>::get(msgType& msg){
...
}
template int A<std::string>::get(std::string& msg);

And then if I use A class with other types other than std::string somewhere, it leads Segmentation fault (core dumped) while loading the C++ shared library.