subobject-linkage error with GCC

Start by reproducing the GCC -Werror=subobject-linkage failure at ../include/sdbusplus/async/timer.hpp:109 with the shown sleep_for coroutine and latest stdexec. Compare the diagnostics from co_await sleep_sender(ctx, time) and co_await execution::schedule(get_scheduler(ctx)); done means both awaits compile without the subobject-linkage error.

This could very well be something wrong with my code. Using the latest stdexec, I'm started seeing this subobject-linkage warning in GCC. It isn't obvious which type is even being called out as a problem.

../include/sdbusplus/async/timer.hpp:109:5: error: ‘sdbusplus::async::timer_ns::sleep_sender::sleep_for(sdbusplus::async::context&, sdbusplus::event::event::time_resolution)::_ZN9sdbusplus5async8timer_ns12sleep_sender9sleep_forERNS0_7contextENSt6chrono8durationIlSt5ratioILl1ELl1000000EEEE.Frame’ has a field ‘stdexec::__as_awaitable::__sender_awaitable<stdexec::_Yp<exec::__task::basic_task<void, exec::__task::__default_task_context_impl<exec::__task::__scheduler_affinity::__sticky> >::__promise>, stdexec::__sexpr<stdexec::__detail::{anonymous}::<lambda(_Tag, _Captures&& ...)>::<lambda(_Cvref, _Fun&&)> > >::__t sdbusplus::async::timer_ns::sleep_sender::sleep_for(sdbusplus::async::context&, sdbusplus::event::event::time_resolution)::_ZN9sdbusplus5async8timer_ns12sleep_sender9sleep_forERNS0_7contextENSt6chrono8durationIlSt5ratioILl1ELl1000000EEEE.Frame::Aw1_2_4’ whose type has internal linkage [-Werror=subobject-linkage]

The affected code is a rather simple co-routine using the stdexec task.

    static task<> sleep_for(context& ctx, event_t::time_resolution time)
    {
        // Run the delay sender and then switch back to the worker thread.
        // The delay completion happens from the sd-event handler, which is
        // ran on the 'caller' thread.
        co_await sleep_sender(ctx, time);
        co_await execution::schedule(get_scheduler(ctx));
    }

Both co_awaits have this subobject-linkage problem, so even if I comment out the first one I still end up with it.