+* PID 1 should send out sd_notify("WATCHDOG=1") messages (for usage in the --user mode, and when run via nspawn)
+
+* nspawn should send out sd_notify("WATCHDOG=1") messages
+
+* nspawn should optionally support receiving WATCHDOG=1 messages from its payload PID 1...
+
+* introduce "machinectl shell" that is like systemd-run -M foo /bin/bash -t but also adds PAMName=login
+
+* allow loging into host with "machinectl login".
+
+* consider throwing a warning if a service declares it wants to be "Before=" a .device unit.
+