The original idea behind this change (described in ticket #11064) was to
improve the assertions to avoid that users of the X server accidentally
forget to configure a DM or WM.
However this caused several issues with setups that require X, but no DM
or WM. The keymap testcases became instable as well as now disabling DMs
needs to be done explicitly.
(see https://github.com/NixOS/nixpkgs/pull/31268#issuecomment-347080036)
In the end the idea behind the change and #11064 was obviously a
mistake, so reverting it completely for now should be fine.
Eelco Dolstra wrote:
Hm, this is not really the intended use of stateVersion. From the description:
Every once in a while, a new NixOS release may change
configuration defaults in a way incompatible with stateful
data. For instance, if the default version of PostgreSQL
changes, the new version will probably be unable to read your
existing databases. To prevent such breakage, you can set the
value of this option to the NixOS release with which you want
to be compatible. The effect is that NixOS will option
defaults corresponding to the specified release (such as using
an older version of PostgreSQL).
So this is only intended for options that have some corresponding on-disk state. AFAICT this is not the case for sound. In any case stateVersion is a necessary evil that only exists because we can't just upgrade Postgres databases or change SSH host keys. It's not necessary for things like whether sound is enabled. (If the user discovers that sound is suddenly disabled, they can just enable it.)
I had some vague recollection that we also had a configVersion option setting to control the defaults for non-state-related options, but I can't find it so maybe it was only discussed.
addPassthru became unused in #33057, but its signature was changed at the same
time. This commit restores the original signature and updates the warning and
the changelog.
This was only applicable to very specific hardware, and the only person
with an apparent interest in maintaining it (me) no longer uses the
hardware in question.
before:
- /var/run/memcached is a bad default for a socket path, since its
parent directory must be writeable by memcached.
- Socket directory was not created by the module itself -> this was
left as a burden to the user?
- Having a static uid with a dynamic user name is not very useful.
after:
- Replace services.memcached.socket by a boolean flag. This simplifies
our code, since we do not have to check if the user specifies a
path with a parent directory that should be owned by memcached
(/run/memcached/memcached.sock -> /run/memcached).
- Remove fixed uid/gid allocation. The only file ever owned by the
daemon is the socket that will be recreated on every start.
Therefore user and group ids do not need to be static.
- only create the memcached user, if the user has not specified a
different one. The major use case for changing option is to allow
existing services (such as php-fpm) opening the local unix socket.
If we would unconditionally create a user that option would be
useless.
