It seems I missed the addition of s6-svscan's -X option; I saw it one day in the output of 'ps' on a VM that was using s6-linux-init, didn't recognize it, but then forgot to look up what it did :P But I would have to 'tag' messages in some way, so that the catch-all logger recognizes them and sends them to the terminal, right?
Yes. That's why it's the "advanced" solution over just leaking a fd for /dev/tty.
Anyway, nosetsid + /dev/tty is still the simplest implementation, I have to admit.
The more I think about it, the more I see any use of nosetsid as incorrect. Implementing SIGINT handling for s6-supervise requires jumping through serious hoops if the nosetsid function still exists, and the point of my current work on s6 is to get things simpler, not more complex. I'm leaning more and more in the direction of removing nosetsid, which is why I want to help people find other ways to accomplish what they're currently doing with it. -- Laurent