gcc/g++ internal error (c++ templated lambda)

i was just making a few changes to my program, when all of a sudden g++ complained with an internal compiler error.

Clang however compiles it without any problems and also does not give any warnings, that would indicate anything weird.

I distilled the problem down to this:

main.cpp

#include "B.hpp"

int main(int argc, char** argv){
    B<int> a;
    return 0;
}

B.hpp

#include "A.hpp"

#include <iostream>
#include <functional>

template<typename T>
class B {
        int x;

        std::function<A<double>(A<int>&)> someLambda = [&](A<int>& aInt){
            int xVar = x;
            std::cout << std::to_string(xVar);

            A<double> aRet;
            return aRet;
        };
};

A.hpp

template<typename T>
class A{
    T someVar;
};

I tried both GCC 4.9.2 and 4.8.4, with both failing (internal compiler error).

Flags I used:

g++ -std=c++11 -O0 -g -Wall main.cpp -o gccBin

clang++ -std=c++11 -O0 -g -Wall main.cpp -o clangBin

In file included from main.cpp:1:0:
B.hpp: In instantiation of ‘struct B<int>::<lambda(class A<int>&)>’:
B.hpp:7:7:   required from here
B.hpp:11:15: internal compiler error: in tsubst_copy, at cp/pt.c:12569
    int xVar = x;
               ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://ift.tt/1v5WCGL; for instructions.

Clang++(3.5.1) compiles it without a problem, as I mentioned. I also tried multiple machines, everywhere the same.

Is there some kind of error I overlooked? I searched a bit on the internet and the only similar problems i could find should have been fixed by now (as the bugtracker states).

Could maybe someone try and run this code on their machine or give other advice?

Thank you,

Lazarus