they exist:
• If the local group ‘nss-nonlocal-users’ exists, then nonlocal users
- will be automatically added to it.
+ will be automatically added to it. Furthermore, if a local user is
+ added to this group, then that user will inherit any nonlocal
+ supplementary gids from a nonlocal user of the same name.
• If the local group ‘nss-local-users’ exists, then local users will
be automatically added to it.