Comment 13 for bug 1816753

Verified 229-4ubuntu21.19 on Xenial:

# systemd-detect-virt --container
wsl

...
root@x-uu-upgrade:~# systemd-detect-virt
lxc
oot@x-uu-upgrade:~# dpkg -l systemd | cat
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-================-============-=================================
ii systemd 229-4ubuntu21.19 amd64 system and service manager
...

...
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ systemd-detect-virt --container
none
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ echo $?
1
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ dpkg -l systemd | cat
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-================-============-===========================
...