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mirror of https://github.com/NixOS/mobile-nixos.git synced 2024-12-16 20:21:32 +03:00
mobile-nixos/lib/eval-with-configuration.nix
2021-02-23 21:05:28 -05:00

89 lines
2.9 KiB
Nix

# This is a shim that calls `evalWithConfiguration` automatically, with
# some additional helpers.
# This replaces the previously quite un-hermetic `default.nix` inclusion.
# This is meant for use internally by Mobile NixOS, the interface here
# should not be assumed to be *stable*.
{
pkgs ? import <nixpkgs> {}
# The identifier of the device this should be built for.
# (This gets massaged later on)
, device ? null
, configuration
# Internally used to tack on configuration by release.nix
, additionalConfiguration ? {}
, additionalHelpInstructions ? ""
}:
let
inherit (pkgs.lib) optionalString strings;
inherit (strings) concatStringsSep stringAsChars;
# Either use:
# The given `device`.
# The environment variable.
final_device =
if device != null then device
else throw "Please provide a device name using e.g. `--argstr device $DEVICE`."
;
inherit (import ./release-tools.nix { inherit pkgs; }) evalWith;
# The "default" eval.
eval = evalWith {
device = final_device;
modules = configuration;
inherit additionalConfiguration;
};
# Makes a mostly useless header.
# This is mainly useful for batch evals.
header = str:
let
str' = "* ${str} *";
line = stringAsChars (x: "*") str';
in
builtins.trace (concatStringsSep "\ntrace: " [line str' line])
;
in
(
# Don't break if `device` is not set.
if device == null then (id: id) else
if device ? special
then header "Evaluating: ${device.name}"
else if (builtins.tryEval (builtins.isPath device && builtins.pathExists device)).value
then header "Evaluating device from path: ${toString device}"
else header "Evaluating device: ${device}"
)
{
# The build artifacts from the modules system.
inherit (eval.config.system) build;
# The evaluated config
inherit (eval) config;
# The final pkgs set, usable as -A pkgs.[...] on the CLI.
inherit (eval) pkgs;
# The whole (default) eval
inherit eval;
# Evaluating this whole set is counter-productive.
# It'll put a *bunch* of build products from the misc. inherits we added.
# (We're also using `device` to force the other throw to happen first.)
# TODO : We may want to produce an internal list of available outputs, so that
# each platform can document what it makes available. This would allow
# the message to be more user-friendly by displaying a choice.
# Something like `config.mobile.build.proposedOutputs` as a list of pairs [ "outputName" "description" ].
__please-fail = throw ''
Cannot directly build for ${final_device}...
Building this whole set is counter-productive, and not likely to be what
is desired.
${optionalString (additionalHelpInstructions != "") "\n"}${additionalHelpInstructions}
*************************************************
* Please also read your device's documentation. *
* It may contain further usage notes. *
*************************************************
'';
}