Hello,
I just stumbled across the outputs.overlays.default flake sheme and am not sure for what it is good when configuring NixOS with various overlays like my configuration currently does (or in any other way).
A user of Reddit mentioned the option in the context of NixOS, so I tried out the following, but it wouldn’t work (or get the defined overlays applied into my NixOSes pkgs).
outputs = { self, nixpkgs, nixpkgs-unstable, home-manager, sops-nix, plasma-manager, nixvim, ... }@input-attrs:
let system = "x86_64-linux";
in
{
overlays.default = final: prev: {
unstable = import nixpkgs-unstable {
inherit system;
config.allowUnfree = true;
};
};
nixosConfigurations = {
# ...
Any ideas or might I just misunderstand this Reddit guy?
Further Context
This is my whole flake.nix with the overlay defined in the modules section of the nixosSystem, if someone might me interested/ it’s relevant for answering this question.
{
description = "NixOS configuration";
inputs = {
nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
home-manager = {
url = "github:nix-community/home-manager/release-23.11";
inputs.nixpkgs.follows = "nixpkgs";
};
sops-nix = {
url = "github:Mic92/sops-nix";
inputs.nixpkgs.follows = "nixpkgs-unstable"; # TODO ???
inputs.nixpkgs-stable.follows = "nixpkgs";
};
plasma-manager = {
url = "github:pjones/plasma-manager";
inputs.nixpkgs.follows = "nixpkgs";
inputs.home-manager.follows = "home-manager";
};
nixvim = {
url = "github:nix-community/nixvim/nixos-23.11";
inputs.nixpkgs.follows = "nixpkgs";
#inputs.pre-commit-hooks.inputs.nixpkgs-stable.follows = "nixpkgs"; # TODO Doesn't follows the nixvim inputs - bug report?
};
};
outputs = { self, nixpkgs, nixpkgs-unstable, home-manager, sops-nix, plasma-manager, nixvim, ... }@input-attrs:
let system = "x86_64-linux";
in
{
nixosConfigurations = {
dnix = nixpkgs.lib.nixosSystem {
inherit system;
modules = [
({ config, pkgs, lib, ... }@module-attrs:
let
# Build Flags Setup (https://nixos.wiki/wiki/Build_flags#Building_the_whole_system_on_NixOS)
arch = "alderlake"; # "raptorlake"
tune = arch;
platform = {
inherit system;
gcc = { inherit arch tune; };
#rustc = { inherit arch tune; }; # TODO Research build flag attributes for rustc
# https://github.com/NixOS/nixpkgs/blob/ffb71fa3d63ddbbd4f84ca4aa03eabae9061a415/pkgs/development/compilers/rust/rustc.nix
};
# Overlay Setup
## Overlay to disable native compilation of packages with build flags
clean-platform = self: super: {
clean = import nixpkgs {
inherit system;
hostPlatform = {
gcc = { };
rustc = { };
};
};
};
build-fixes = import ./overlays/build-fixes.nix;
packages = import ./overlays/packages.nix module-attrs;
unstable = self: super: {
unstable = import nixpkgs-unstable {
inherit system;
config.allowUnfree = true;
};
};
in
{
nixpkgs.config = {
allowUnfree = true;
permittedInsecurePackages = [ "electron-25.9.0" ];
};
nixpkgs = {
# https://nix.dev/tutorials/cross-compilation.html
#buildPlatform = platform; # platform where the executables are built
hostPlatform = platform; # platform where the executables will run
};
nixpkgs.overlays = [
unstable
clean-platform
build-fixes.don't-build-huge-packages
build-fixes.deactivate-tests-failing-python
build-fixes.deactivate-tests-redis
build-fixes.deactivate-tests-haskell
packages.patched-linux
];
})
# NixOS configuration
./nixos/configuration.nix
# home-manager basic setup & configuration import
home-manager.nixosModules.home-manager
{
home-manager.useGlobalPkgs = true;
home-manager.useUserPackages = true;
home-manager.sharedModules = [
sops-nix.homeManagerModules.sops
plasma-manager.homeManagerModules.plasma-manager
nixvim.homeManagerModules.nixvim
];
home-manager.users.jnnk = import ./home-manager/home.nix; # flakes are git-repo-root & symlink-aware
}
];
};
};
};
}