Overload resolution fails for gcc and c++17

The code below fails to compile with gcc (9.2) and c++17. It does work with clang and MSVC, it also worked up to c++14. What's going on, who is right and is there an easy workaround? Resorted to #defineing the unordered_set overload away for gcc but I'd prefer a 'clean' solution.

#include <unordered_set>
#include <iostream>

struct Stream
{};

template <typename T, typename Alloc, template<typename, typename> class Container>
Stream & operator<< (Stream &stream, const Container<T, Alloc>& container)
{
  std::cout << "container"<< std::endl;
  return stream;
}

template <class K, class Hasher, class Keyeq, class Alloc>
Stream & operator<< (Stream &stream, const std::unordered_set<K, Hasher, Keyeq, Alloc> & container)
{
  std::cout << "unordered_set"<< std::endl;
  return stream;
}

int main()
{
    Stream t;
    std::unordered_set<int> set;
    t << set;

    return 0;
}

Result:

<source>: In function 'int main()':    
<source>:25:7: error: ambiguous overload for 'operator<<' (operand types are 'Stream' and 'std::unordered_set<int>')    
   25 |     t << set;    
      |     ~ ^~ ~~~    
      |     |    |    
      |     |    std::unordered_set<int>    
      |     Stream    
<source>:8:10: note: candidate: 'Stream& operator<<(Stream&, const Container<T, Alloc>&) [with T = int; Alloc = std::hash<int>; Container = std::unordered_set]'    
    8 | Stream & operator<< (Stream &stream, const Container<T, Alloc>& container)    
      |          ^~~~~~~~    
<source>:15:10: note: candidate: 'Stream& operator<<(Stream&, const std::unordered_set<_Value1, _Hash1, _Pred1, _Alloc1>&) [with K = int; Hasher = std::hash<int>; Keyeq = std::equal_to<int>; Alloc = std::allocator<int>]'    
   15 | Stream & operator<< (Stream &stream, const std::unordered_set<K, Hasher, Keyeq, Alloc> & container)    
      |          ^~~~~~~~    
ASM generation compiler returned: 1    
<source>: In function 'int main()':    
<source>:25:7: error: ambiguous overload for 'operator<<' (operand types are 'Stream' and 'std::unordered_set<int>')    
   25 |     t << set;    
      |     ~ ^~ ~~~    
      |     |    |    
      |     |    std::unordered_set<int>    
      |     Stream    
<source>:8:10: note: candidate: 'Stream& operator<<(Stream&, const Container<T, Alloc>&) [with T = int; Alloc = std::hash<int>; Container = std::unordered_set]'    
    8 | Stream & operator<< (Stream &stream, const Container<T, Alloc>& container)    
      |          ^~~~~~~~    
<source>:15:10: note: candidate: 'Stream& operator<<(Stream&, const std::unordered_set<_Value1, _Hash1, _Pred1, _Alloc1>&) [with K = int; Hasher = std::hash<int>; Keyeq = std::equal_to<int>; Alloc = std::allocator<int>]'    
   15 | Stream & operator<< (Stream &stream, const std::unordered_set<K, Hasher, Keyeq, Alloc> & container)    
      |          ^~~~~~~~    
Execution build compiler returned: 1

https://godbolt.org/z/4dGu6L