How to use service definitions from unstable channel?

I’m aware of how to easily get a package from unstable channel:

let
  unstable = import <nixos-unstable> { };
in {
  service.xyz.package = unstable.xyz;
}

As suggested by this post:

But how do I do the same thing for a service definition?
For example, I’ve submitted a PR for syncthing service:

But how can I now use that one service configuration while still using nixos-21.05 channel for everything else?

1 Like

https://nixos.org/manual/nixos/unstable/#sec-replace-modules

3 Likes

Ah, lovely, thank you!