* The environment variables NIX_CONF_DIR, NIX_BUILD_HOOK and
NIX_REMOTE are no longer needed.
* A /bin/sh (from busybox) is provided by default in sandboxes.
* Various options were renamed.
Among other things, this will allow *2nix tools to output plain data
while still being composable with the traditional
callPackage/.override interfaces.
This can be disabled with the `withKerberos` flag if desired.
Make the relevant assertions lazy,
so that if an overlay is used to set kerberos to null,
a later override can explicitly set `withKerberos` to false.
Don't build with GSSAPI by default;
the patchset is large and a bit hairy,
and it is reasonable to follow upstream who has not merged it
in not enabling it by default.
This can be disabled with the `withKerberos` flag if desired.
Make the relevant assertions lazy,
so that if an overlay is used to set kerberos to null,
a later override can explicitly set `withKerberos` to false.
Don't build with GSSAPI by default;
the patchset is large and a bit hairy,
and it is reasonable to follow upstream who has not merged it
in not enabling it by default.
`nixos-generate-config` detects the `cpuFreqGovernor` suited best for my
machine, e.g. `powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";`.
However the `powerManagement` module sets a sensitive default for
`cpuFreqGovernor` using `mkDefault` to avoid breackage with older
setups. Since 140ac2f1 the `hardware-configuration.nix` sets the
gorvernor with `mkDefault` as well which causes evaluation errors if the
powermanagement module is enabled:
```
error: The unique option `powerManagement.cpuFreqGovernor' is defined multiple times, in `/home/ma27/Projects/nixos-config/hardware-configuration.nix' and `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/config/power-management.nix'.
```
Using `mkOptionDefault` rather than `mkDefault` in the powermanagement
module fixes this issue as it decreases the priority of the module and
prefers the value set in `hardware-configuration.nix`.
I have confirmed the change using the following VM declaration:
```
{
cpuFreq = { lib, ... }: {
powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
powerManagement.enable = true;
};
}
```
`services.postfix.config` is now correctly merged with the default attrset
specified in the module. Some options that are lists in postfix also
have to be lists in nix to be merged correctly. Other default options are
now set with `mkDefault` so they can be overridden via the module system.
