4.0 has been out for a year without another upstream release, so
presumably 4.x's quite stable enough (and already in Arch & Debian
Buster for instance).
`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;
};
}
```
This reverts commit bc474e2dd8.
Source hash is incorrect:
https://hydra.nixos.org/build/68234054
And even fixing it doesn't make it compile:
Checking for system tdb (>=1.3.15) : not found
ERROR: System library tdb of version 1.3.15 not found, and bundling disabled
builder for ‘/nix/store/bxnawxa402vrv4qmcmj2hmp98a0bz7li-ldb-1.3.1.drv’ failed with exit code 1
error: build of ‘/nix/store/bxnawxa402vrv4qmcmj2hmp98a0bz7li-ldb-1.3.1.drv’ failed
Tuomas Tynkkynen
Maximilian Bosch
Thomas Mader
adisbladis
Will Dietz
Aneesh Agrawal
adisbladis
Linus Heckemann
Franz Pletz
Michael Raskin
Daiderd Jordan
Matthias Beyer
Sarah Brofeldt
Tom Bereknyei
Michal Rus
Renato Alves
Alexey Shmalko
Symphorien Gibol
zimbatm
Robert Schütz
Sam Parkinson
Andreas Rammhold