Luke Granger-Brown
57725ef3ec
git-subtree-dir: third_party/nixpkgs git-subtree-split: 76612b17c0ce71689921ca12d9ffdc9c23ce40b2
102 lines
4.1 KiB
Nix
102 lines
4.1 KiB
Nix
{ config, options, lib, pkgs, ... }:
|
|
let
|
|
cfg = config.nixpkgs.flake;
|
|
in
|
|
{
|
|
options.nixpkgs.flake = {
|
|
source = lib.mkOption {
|
|
# In newer Nix versions, particularly with lazy trees, outPath of
|
|
# flakes becomes a Nix-language path object. We deliberately allow this
|
|
# to gracefully come through the interface in discussion with @roberth.
|
|
#
|
|
# See: https://github.com/NixOS/nixpkgs/pull/278522#discussion_r1460292639
|
|
type = lib.types.nullOr (lib.types.either lib.types.str lib.types.path);
|
|
|
|
default = null;
|
|
defaultText = "if (using nixpkgsFlake.lib.nixosSystem) then self.outPath else null";
|
|
|
|
example = ''builtins.fetchTarball { name = "source"; sha256 = "${lib.fakeHash}"; url = "https://github.com/nixos/nixpkgs/archive/somecommit.tar.gz"; }'';
|
|
|
|
description = ''
|
|
The path to the nixpkgs sources used to build the system. This is automatically set up to be
|
|
the store path of the nixpkgs flake used to build the system if using
|
|
`nixpkgs.lib.nixosSystem`, and is otherwise null by default.
|
|
|
|
This can also be optionally set if the NixOS system is not built with a flake but still uses
|
|
pinned sources: set this to the store path for the nixpkgs sources used to build the system,
|
|
as may be obtained by `builtins.fetchTarball`, for example.
|
|
|
|
Note: the name of the store path must be "source" due to
|
|
<https://github.com/NixOS/nix/issues/7075>.
|
|
'';
|
|
};
|
|
|
|
setNixPath = lib.mkOption {
|
|
type = lib.types.bool;
|
|
|
|
default = cfg.source != null;
|
|
defaultText = "config.nixpkgs.flake.source != null";
|
|
|
|
description = ''
|
|
Whether to set {env}`NIX_PATH` to include `nixpkgs=flake:nixpkgs` such that `<nixpkgs>`
|
|
lookups receive the version of nixpkgs that the system was built with, in concert with
|
|
{option}`nixpkgs.flake.setFlakeRegistry`.
|
|
|
|
This is on by default for NixOS configurations built with flakes.
|
|
|
|
This makes {command}`nix-build '<nixpkgs>' -A hello` work out of the box on flake systems.
|
|
|
|
Note that this option makes the NixOS closure depend on the nixpkgs sources, which may add
|
|
undesired closure size if the system will not have any nix commands run on it.
|
|
'';
|
|
};
|
|
|
|
setFlakeRegistry = lib.mkOption {
|
|
type = lib.types.bool;
|
|
|
|
default = cfg.source != null;
|
|
defaultText = "config.nixpkgs.flake.source != null";
|
|
|
|
description = ''
|
|
Whether to pin nixpkgs in the system-wide flake registry (`/etc/nix/registry.json`) to the
|
|
store path of the sources of nixpkgs used to build the NixOS system.
|
|
|
|
This is on by default for NixOS configurations built with flakes.
|
|
|
|
This option makes {command}`nix run nixpkgs#hello` reuse dependencies from the system, avoid
|
|
refetching nixpkgs, and have a consistent result every time.
|
|
|
|
Note that this option makes the NixOS closure depend on the nixpkgs sources, which may add
|
|
undesired closure size if the system will not have any nix commands run on it.
|
|
'';
|
|
};
|
|
};
|
|
|
|
config = lib.mkIf (cfg.source != null) (lib.mkMerge [
|
|
{
|
|
assertions = [
|
|
{
|
|
assertion = cfg.setNixPath -> cfg.setFlakeRegistry;
|
|
message = ''
|
|
Setting `nixpkgs.flake.setNixPath` requires that `nixpkgs.flake.setFlakeRegistry` also
|
|
be set, since it is implemented in terms of indirection through the flake registry.
|
|
'';
|
|
}
|
|
];
|
|
}
|
|
(lib.mkIf cfg.setFlakeRegistry {
|
|
nix.registry.nixpkgs.to = lib.mkDefault {
|
|
type = "path";
|
|
path = cfg.source;
|
|
};
|
|
})
|
|
(lib.mkIf cfg.setNixPath {
|
|
# N.B. This does not include nixos-config in NIX_PATH unlike modules/config/nix-channel.nix
|
|
# because we would need some kind of evil shim taking the *calling* flake's self path,
|
|
# perhaps, to ever make that work (in order to know where the Nix expr for the system came
|
|
# from and how to call it).
|
|
nix.nixPath = lib.mkDefault ([ "nixpkgs=flake:nixpkgs" ]
|
|
++ lib.optional config.nix.channel.enable "/nix/var/nix/profiles/per-user/root/channels");
|
|
})
|
|
]);
|
|
}
|