root@dakara:~# useradd --system blah
root@dakaracat /etc/subgid lxd:100000:65536 root:100000:65536 sshd:165536:65536 sbuild:231072:65536 blah:296608:65536
blah most definitely shouldn't be there!
root@dakara:~# useradd --system blah
root@dakaracat /etc/subgid
lxd:100000:65536
root:100000:65536
sshd:165536:65536
sbuild:231072:65536
blah:296608:65536
blah most definitely shouldn't be there!