Gentoo's Bugzilla –
Attachment 881524 Details for
Bug 921430kde-plasma/kwayland-integration-5.91.0 fails to compile (lto): src/windowsystem/qwayland-wayland.h:174:14: error: type ‘QtWayland::wl_shm::format’ violates the C++ One Definition Rule [-Werror=odr]