https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118014
--- Comment #1 from Giel <giel+gcc at mortis dot eu> --- While different from PR104177 I believe that Arsen's patch for that would also solve this bug: [PATCH 2/2] c++/coroutines: handle (new-)extended alignment [PR104177] (https://gcc.gnu.org/pipermail/gcc-patches/2024-September/663295.html) This is because that patch makes the offset between the promise and coroutine frame (pointer) dependent *only* on sizeof(void*) and thus independent of alignof(T). Eliminating any differences between alignof(Base) and alignof(Derived).