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.
This allows one to specify "related packages" in NixOS that get rendered into
the configuration.nix(5) man page. The interface philosophy is pretty much
stolen from TeX bibliography.
See the next several commits for examples.
The use of Nix 2.0 significantly simplifies the installer, since we
can just pass a different store URI (--store /mnt) - it's no longer
needed to set up a chroot environment for the build, and to bootstrap
Nix into the chroot.
Also, commands that need to run in the installation (namely boot
loader installation and setting a root password) are now executed
using nixos-enter.
This also removes the need for nixos-prepare-root since any required
initialisation is done by Nix or by the activation script.
Among other things, this will allow *2nix tools to output plain data
while still being composable with the traditional
callPackage/.override interfaces.
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.
