anchor.diff:        home.file =
           listToAttrs (
             (buildServices "service" cfg.services)
  +          ++
  +          (buildServices "socket" cfg.sockets)
             ++
             (buildServices "target" cfg.targets)
             ++
  
positive.code: 
    cfg = config.systemd.user;
  
    enabled = cfg.services != {} || cfg.targets != {} || cfg.timers != {};
  
    toSystemdIni = (import lib/generators.nix).toINI {
      mkKeyValue = key: value:
  
negative.code:           message =
              let
                names = concatStringsSep ", " (
                    attrNames (
                        cfg.services // cfg.sockets // cfg.targets // cfg.timers
                    )
                );
              in
                "Must use Linux for modules that require systemd: " + names;
  