Chris SiebenmannIt turns out that all sorts of fun and weird things happen on a modern Linux machine when the system D-Bus daemon dies, even on a server. As they say, ask me how I know.
JdeBPThe opposite is fun, too: when there's a system #DesktopBus broker running but it's not a systemd system, and logging in through a chain of intertwined mechanisms tries to auto-start #systemd.