On Fri, Feb 14, 2020 at 12:42 PM Thomas Deutschmann <whi...@gentoo.org> wrote: > > > # usermod -aG thomas postfix > > # id postfix > > uid=207(postfix) gid=207(postfix) > groups=207(postfix),12(mail),1004(thomas) > > # emerge -a1 acct-user/postfix > > [...] > > > > >>> Installing (1 of 1) acct-user/postfix-0::gentoo > > * checking 0 files for package collisions > > >>> Merging acct-user/postfix-0 to / > > >>> Safely unmerging already-installed instance... > > No package files given... Grabbing a set. > > >>> Regenerating /etc/ld.so.cache... > > >>> Original instance of package unmerged safely. > > * Updating groups for user 'postfix' ... > > * - Groups: postfix,mail > > >>> acct-user/postfix-0 merged. > > >>> Auto-cleaning packages... > > > > [...] > > > > # id postfix > > uid=207(postfix) gid=207(postfix) groups=207(postfix),12(mail) > >
There's a significant difference between changing group membership for a system user versus a user account that is used interactively. I don't think the handbook advises people to mess with system accounts.