Question: can sender be notified of receiver shutdown?

[maddanio]

I only saw the timeout feature. But is it not possible to get a failure response directly if the target is shut diwn?

[maddanio]

I have skimmed the implementation, and to me it seems supervisor_t::on_child_shutdown actually could do this? it would just have to check its message box for requests to that actor and schedule an error response.

[basiliscos]

I only saw the timeout feature. But is it not possible to get a failure response directly if the target is shut diwn?

there is a request-response mechanism, and you receive response with "timeout" when there is no answer (it does not matter why: it might be no target, target is down, target is not subscribed etc.)