@cazabon @landley Grats!

Switching from runit to s6 should be easy: your service directories basically don't change, unless you want to adapt them to use s6-specific features such as readiness notification.

The only difficult (and it's "difficult" in the sense that it requires a bit of work, not that you need l33t skill or arcane knowledge) part would be s6-linux-init installation, since unlike runit, s6 doesn't natively come with its own pid 1 process; s6-linux-init is the package that performs the necessary little dance so that s6-svscan can run as your pid 1 for the rest of the machine's lifetime.

You can look at this post from heliocat https://www.reddit.com/r/voidlinux/comments/khn1jy/adventures_in_booting_void_on_s6/ who has done exactly that, not on Devuan, but on Void. You can probably ignore everything about s6-rc, which is the advanced level: for a simple runit-to-s6 conversion, you need s6 and s6-linux-init, and that's it.

The s6 and s6-linux-init documentation should be clear enough, especially since daemontools-like have no secrets for you, but if you need support, come to the #s6 IRC channel on OFTC and we'll be delighted to have you 😉