for example in `systemd-nspawn`, will be logged to the audit log, if the
kernel supports this.
+* `$SYSTEMD_ENABLE_LOG_CONTEXT` — if set, extra fields will always be logged to
+the journal instead of only when logging in debug mode.
+
`systemctl`:
* `$SYSTEMCTL_FORCE_BUS=1` — if set, do not connect to PID 1's private D-Bus