Simple coroutine leaking with GCC 10

Consider the following simple coroutine, which tracks its construction and destruction:

#include <coroutine>#include <iostream>struct simple {  static inline int x = 0;  int id = 0;  simple() : id{ x++ } { std::cout << id << " constructed\n"; }  simple(simple&&) : id{ x++ } { std::cout << id << " move constructed\n"; }  ~simple() { std::cout << id << " destructed\n"; }  struct promise_type {    simple get_return_object() { return {}; }    void return_void() {}    void unhandled_exception() { std::terminate(); }    auto initial_suspend() noexcept { return std::suspend_never{}; }    auto final_suspend() noexcept { return std::suspend_never{}; }  };};simple f() { co_return; }int main() {  f();}

When compiling with GCC 10.1, the output is:

0 constructed1 move constructed1 destructed

—notably, id 0 is never destructed. This is true even with GCC trunk.

Is there something I've done wrong here, some hidden UB or the like? Or is GCC at fault here?

As a comparison, I tried using Clang's experimental coroutine support, and got

0 constructed0 destructed

which is closer to what I was expecting. I also get this "correct" output even in GCC if I comment out the move constructor in the coroutine object.

Live example: https://godbolt.org/z/UQVURi