Hi, [disclaimer: on work on systemd upstream, I'm not an active Debian user anymore.]
Using systemd-sysusers and systemd-tmpfiles more widely was mentioned a few times, along with a statement that an implementation for non-systemd systems would need to be provided. Both those programs work just fine without systemd not running as PID1. (systemd has unit files to start them automatically during boot and at regular intervals, so that part would need to be reimplemented appropriately for a given init system if desired. The programs themselves don't care at all how they are started.) For example, upstream distributes rpm scriptlets [1] to invoke them from an rpm transaction, i.e. possibly without any programs running in the install root. [1] https://github.com/systemd/systemd/blob/master/src/core/macros.systemd.in#L123 Zbyszek
