nixos-module/overlay.nix
jade de3c854615 Warn on mismatched Lix module version
Especially with nixpkgs being an extremely uncontrolled variable, we
cannot guarantee that the module is always the right version. This will
cause support burden, so let's automatically diagnose it.
2024-07-30 15:13:24 -07:00

110 lines
4.3 KiB
Nix

{ lix ? null, versionSuffix ? "" }:
final: prev:
let
# This is kind of scary to not override the nix version to pretend to be
# 2.18 since nixpkgs can introduce new breakage in its Nix unstable CLI
# usage.
# https://github.com/nixos/nixpkgs/blob/6afb255d976f85f3359e4929abd6f5149c323a02/nixos/modules/config/nix.nix#L121
lixPackageFromSource = final.callPackage (lix + "/package.nix") ({
versionSuffix = "-${versionSuffix}";
# FIXME: do this more sensibly for future releases
# https://git.lix.systems/lix-project/lix/issues/406
officialRelease = false;
});
# These packages depend on Nix features that Lix does not support
overridelist_2_18 = [
"attic-client"
"devenv"
"nix-du"
"nix-init"
"nix-prefetch-git"
"nixos-option"
"nurl"
"prefetch-yarn-deps" # force these onto upstream so we are not regularly rebuilding electron
];
override_2_18 = prev.lib.genAttrs overridelist_2_18 (
name: prev.${name}.override {
nix = final.nixVersions.nix_2_18_upstream;
});
inherit (prev) lib;
csi = builtins.fromJSON ''"\u001b"'';
orange = "${csi}[35;1m";
normal = "${csi}[0m";
warning = ''
${orange}warning${normal}: You have the lix overlay included into a nixpkgs import twice,
perhaps due to the NixOS module being included twice, or because of using
pkgs.nixos and also including it in imports, or perhaps some unknown
machinations of a complicated flake library.
This is completely harmless since we have no-op'd the second one if you are
seeing this message, but it would be a small style improvement to fix
it :)
P.S. If you had some hack to fix nixos-option build failures in your
configuration, that was caused by including an older version of the lix
overlay twice, which is now mitigated if you see this message, so you can
delete that.
P.P.S. This Lix has super catgirl powers.
'';
wrongMajorWarning = ''
${orange}warning${normal}: This Lix NixOS module is being built against a Lix with a
major version (got ${lixPackageToUse.version}) other than the one the
module was designed for (expecting ${supportedLixMajor}). Some downstream
packages like nix-eval-jobs may be broken by this. Consider using a
matching version of the Lix NixOS module to the version of Lix you are
using.
'';
maybeWarnDuplicate = x: if final.lix-overlay-present > 1 then builtins.trace warning x else x;
versionJson = builtins.fromJSON (builtins.readFile ./version.json);
supportedLixMajor = builtins.elemAt (builtins.match ''^([[:digit:]]+\.[[:digit:]]+)\..*'' versionJson.version) 0;
lixPackageToUse = if lix != null then lixPackageFromSource else prev.lix;
# Especially if using Lix from nixpkgs, it is plausible that the overlay
# could be used against the wrong Lix major version and cause confusing build
# errors. This is a simple safeguard to put in at least something that might be seen.
maybeWarnWrongMajor = x: if !(lib.hasPrefix supportedLixMajor lixPackageToUse.version) then builtins.trace wrongMajorWarning x else x;
overlay = override_2_18 // {
lix-overlay-present = 1;
# used for things that one wouldn't necessarily want to update, but we
# nevertheless shove it in the overlay and fixed-point it in case one *does*
# want to do that.
lix-sources = import ./pins.nix;
lix = maybeWarnWrongMajor (maybeWarnDuplicate lixPackageToUse);
nixVersions = prev.nixVersions // rec {
nix_2_18 = final.lix;
stable = nix_2_18;
nix_2_18_upstream = prev.nixVersions.nix_2_18;
};
nix-eval-jobs = (prev.nix-eval-jobs.override {
# lix
nix = final.nixVersions.nix_2_18;
}).overrideAttrs (old:
let src = final.lix-sources.nix-eval-jobs;
in {
version = "2.91.0-lix-${builtins.substring 0 7 src.rev}";
# FIXME: should this be patches instead?
inherit src;
mesonBuildType = "debugoptimized";
ninjaFlags = old.ninjaFlags or [ ] ++ [ "-v" ];
}
);
nix-doc = prev.callPackage ./nix-doc/package.nix { withPlugin = false; };
pegtl = prev.callPackage ./pegtl.nix { };
};
in
# Make the overlay idempotent, since flakes passing nixos modules around by
# value and many other things make it way too easy to include the overlay
# twice
if (prev ? lix-overlay-present) then { lix-overlay-present = 2; } else overlay