Comment 8 for bug 1814355

As for the questions of xnox:
"""
ubuntu@autopkgtest:~$ sudo systemd-run --unit=check-env /usr/bin/env
Running as unit: check-env.service
ubuntu@autopkgtest:~$ sudo journalctl --no-pager -u check-env
-- Logs begin at Mon 2018-07-23 18:30:47 CEST, end at Sun 2019-02-03 13:25:21 CET. --
Feb 03 13:25:21 autopkgtest systemd[1]: Started /usr/bin/env.
Feb 03 13:25:21 autopkgtest env[543]: LANG=en_US.UTF-8
Feb 03 13:25:21 autopkgtest env[543]: PATH=/sbin:/usr/sbin:/bin:/usr/bin:/snap/bin
Feb 03 13:25:21 autopkgtest env[543]: INVOCATION_ID=4c9b05e577224d6284cc641778807a16
Feb 03 13:25:21 autopkgtest env[543]: JOURNAL_STREAM=9:18437
ubuntu@autopkgtest:~$ cat /etc/systemd/system.conf
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See systemd-system.conf(5) for details.

[Manager]
#LogLevel=info
#LogTarget=journal-or-kmsg
#LogColor=yes
#LogLocation=no
#DumpCore=yes
#ShowStatus=yes
#CrashChangeVT=no
#CrashShell=no
#CrashReboot=no
#CtrlAltDelBurstAction=reboot-force
#CPUAffinity=1 2
#JoinControllers=cpu,cpuacct net_cls,net_prio
#RuntimeWatchdogSec=0
#ShutdownWatchdogSec=10min
#CapabilityBoundingSet=
#SystemCallArchitectures=
#TimerSlackNSec=
#DefaultTimerAccuracySec=1min
#DefaultStandardOutput=journal
#DefaultStandardError=inherit
#DefaultTimeoutStartSec=90s
#DefaultTimeoutStopSec=90s
#DefaultRestartSec=100ms
#DefaultStartLimitIntervalSec=10s
#DefaultStartLimitBurst=5
#DefaultEnvironment=
#DefaultCPUAccounting=no
#DefaultIOAccounting=no
#DefaultIPAccounting=no
#DefaultBlockIOAccounting=no
#DefaultMemoryAccounting=no
#DefaultTasksAccounting=yes
#DefaultTasksMax=
#DefaultLimitCPU=
#DefaultLimitFSIZE=
#DefaultLimitDATA=
#DefaultLimitSTACK=
#DefaultLimitCORE=
#DefaultLimitRSS=
#DefaultLimitNOFILE=
#DefaultLimitAS=
#DefaultLimitNPROC=
#DefaultLimitMEMLOCK=
#DefaultLimitLOCKS=
#DefaultLimitSIGPENDING=
#DefaultLimitMSGQUEUE=
#DefaultLimitNICE=
#DefaultLimitRTPRIO=
#DefaultLimitRTTIME=
#IPAddressAllow=
#IPAddressDeny=
ubuntu@autopkgtest:~$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=UUID=991dab44-ecab-46c0-be75-150dbea660be ro console=ttyS0
ubuntu@autopkgtest:~$ journalctl -b -k | grep -e initrd -e command
Feb 03 13:23:52 autopkgtest kernel: Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=UUID=991dab44-ecab-46c0-be75-150dbea660be ro console=ttyS0
Feb 03 13:23:52 autopkgtest kernel: Freeing initrd memory: 50848K
ubuntu@autopkgtest:~$ ls /usr/lib/systemd/system-environment-generators/
snapd-env-generator
"""