NixOS notes

.md

Some stuff I've had to figure out that wasn't documented...

Proprietary AMD drivers (fglrx)

If you get this error:

/tmp/nix-build-ati-drivers-15.7-4.4.18.drv-0/common/lib/modules/fglrx/build_mod/2.6.x/firegl_public.c:194:22: fatal error: asm/i387.h: No such file or directory

... it's because the drivers are not compatible with your current kernel version. I've worked around it by adding this to my configuration.nix, to switch to a 4.1 kernel:

{
  # ...
  boot.kernelPackages = plgs.linuxPackages_4_1;
  # ...
}

Installing a few packages from master

1. git clone https://github.com/NixOS/nixpkgs.git /etc/nixos/nixpkgs-master
2. Edit your /etc/nixos/configuration.nix like this:

{ config, pkgs, ... }:

let
  nixpkgsMaster = import ./nixpkgs-master {};
  
  stablePackages = with pkgs; [
    # This is where your packages from stable nixpkgs go
  ];
  
  masterPackages = with nixpkgsMaster; [
    # This is where your packages from `master` go
    nodejs-6_x
  ];
in {
  # This is where your normal config goes, we've just added a `let` block
  
  environment = {
    # ...
    
    systemPackages = stablePackages ++ masterPackages;
  };
  
  # ...
}

GRUB2 on UEFI

This works fine. You need your boot section configured like this:

{
  # ...
  boot = {
    loader = {
      gummiboot.enable = false;
      
      efi = {
        canTouchEfiVariables = true;
      };
      
      grub = {
        enable = true;
        device = "nodev";
        version = 2;
        efiSupport = true;
      };
    };
  };
  # ...
}

Unblock ports in the firewall

The firewall is enabled by default. This is how you open a port:

{
  # ...
  networking = {
    # ...
    
    firewall = {
      allowedTCPPorts = [ 24800 ];
    };
  };
  # ...
}

Guake doesn't start because of a GConf issue

1. Read the following warning: GNOME's GConf implements a system-wide registry (like on Windows) that applications can use to store and retrieve internal configuration data. That concept is inherently impure, and it's very hard to support on NixOS.
2. ... but, Guake isn't going to work otherwise, so follow the instructions here.
3. Run the following to set up the GConf schema for Guake: gconftool-2 --install-schema-file $(readlink $(which guake) | grep -Eo '\/nix\/store\/[^\/]+\/')"share/gconf/schemas/guake.schemas". This will not work if you have changed your Nix store path - in that case, modify the command accordingly.

You may need to re-login to make the changes apply.

FFMpeg support in youtube-dl

Based on this post:

{
  # ...
  stablePackages = with pkgs; [
    # ...
    (python35Packages.youtube-dl.override {
      ffmpeg = ffmpeg-full;
    })
    # ...
  ];
  # ...
}

(To understand what stablePackages is here, see this entry.)