Perl seems to write the file in latin1 independent of the actual input
encoding. This can corrupt the "description" field of /etc/passwd. By
setting "binmode" to ":utf8" Perl can be forced to write UTF-8. Ideally
the program would simply read/write the fields by value without any
changes in encoding. However, assuming/enforcing UTF-8 is a lot better
than using an obsolete coding like latin1.
I.e. don't call "passwd" to update /etc/shadow from the "password"
option. This has the side-effect of not updating the password if
mutableUsers = true (since the code path for "hashedPassword" has a
check for mutableUsers).
Fixes #4747.
With mutableUsers = true, we now ensure that all users and groups that
were created declaratively, are updated or removed
appropriately. Thus, adding a user to users.extraUsers and then
removing it now causes the acoount to be removed from
/etc/passwd. Thus user/group management is fully congruent except that
users and groups that were created imperatively (via useradd/groupadd)
are not touched. We distinguish between declarative and imperative
users/groups by tracking the former in
/var/lib/nixos/declarative-{groups,users}.
With mutableUsers = false, you are now no longer required to specify
UIDs/GIDs for all users. The handling of mutableUsers = true/false is
the same code path; the only difference is that the "false" mode
ignores the existing contents of /etc/{passwd,group}.
The attribute ‘createUser’ is gone. It doesn't really make sense to
specify users that shouldn't be created.
