fix nixpkgs.channels system

cerulean/default.nix

@@ -15,14 +15,19 @@
   mix,
   deploy-rs,
   ...
-} @ inputs:
-mix.newMixture inputs (mixture: {
+} @ args:
+mix.newMixture args (mixture: {
   includes.public = [
     ./nexus
   ];
 
   version = "0.1.0";
 
+  nixosModules = rec {
+    default = cerulean;
+    cerulean = ./nixos-module;
+  };
+
   overlays = [
     # build deploy-rs as a package not from the flake input,
     # hence we can rely on a nixpkg binary cache.

cerulean/nexus/default.nix

@@ -11,8 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-{mix, ...} @ inputs:
-mix.newMixture inputs (mixture: {
+{mix, ...} @ args:
+mix.newMixture args (mixture: {
   includes.public = [
     ./nodes.nix
     ./nexus.nix

cerulean/nexus/nexus.nix

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 {
+  self,
   this,
   nt,
   lib,
@@ -184,15 +185,18 @@ in {
         nodeName: node: let
           nixosDecl = lib.nixosSystem {
             system = node.system;
+            specialArgs = let
               specialArgs =
                 nexus.specialArgs
                 // node.specialArgs
                 // {
-                inherit root;
+                  inherit root specialArgs;
                   inherit (node) system;
                 };
+            in
+              specialArgs;
             modules =
-              [../nixos-module (findImport (root + "/hosts/${nodeName}"))]
+              [self.nixosModules.default (findImport (root + "/hosts/${nodeName}"))]
               ++ (getGroupModules root nodeName node)
               ++ node.extraModules
               ++ nexus.extraModules;

cerulean/nixos-module/default.nix

@@ -11,9 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-{deploy-rs, ...}: {
+{
+  root,
+  deploy-rs,
+  ...
+} @ args: {
   imports = [
-    ./nixpkgs.nix
+    # user configuration
+    (import (root + "/nixpkgs.nix"))
+    # options declarations
+    (import ./nixpkgs.nix (args // {contextName = "hosts";}))
+
     ./home-manager.nix
   ];
 

cerulean/nixos-module/home-manager.nix

@@ -15,15 +15,27 @@
   root,
   config,
   lib,
+  specialArgs,
   ...
-} @ args: {
+} @ args: let
+  inherit
+    (builtins)
+    attrNames
+    filter
+    pathExists
+    ;
+in {
   home-manager = {
     users =
       config.users.users
-      |> builtins.attrNames
-      |> builtins.filter (x: builtins.pathExists (root + "/homes/${x}"))
+      |> attrNames
+      |> filter (x: pathExists (root + "/homes/${x}"))
       |> (x: lib.genAttrs x (y: import (root + "/homes/${y}")));
 
-    extraSpecialArgs = args;
+    extraSpecialArgs = specialArgs;
+    sharedModules = [
+      (import (root + "/nixpkgs.nix"))
+      (import ./nixpkgs.nix (args // {contextName = "homes";}))
+    ];
   };
 }

cerulean/nixos-module/nixpkgs.nix

@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 {
-  nt,
   lib,
+  system,
   config,
+  contextName,
   ...
 }: let
   inherit
@@ -22,18 +23,14 @@
     mapAttrs
     ;
 
-  inherit
-    (nt)
-    flip
-    ;
-
-  cfg = config.pkgsrc;
+  cfg = config.nixpkgs.channels;
 in {
-  options.pkgsrc = lib.mkOption {
-    type = lib.types.attrsOf lib.types.attrs;
+  options.nixpkgs.channels = lib.mkOption {
+    type = lib.types.attrsOf (lib.types.attrs);
     default = {};
-    description = "Declare and import custom package repositories.";
+    description = "Declare package repositories per module context (nixos, home-manager, etc)";
     example = {
+      "homes" = {
         "pkgs" = {
           source = "inputs.nixpkgs";
           system = "x86-64-linux";
@@ -42,42 +39,52 @@ in {
             allowBroken = false;
           };
         };
+        "upkgs" = {
+          source = "inputs.nixpkgs-unstable";
+          system = "x86-64-linux";
+          config = {
+            allowUnfree = true;
+            allowBroken = false;
+          };
+        };
+      };
     };
   };
 
+  # or abort ''
+  #         `nixpkgs.channels.${contextName}` does not exist, but neither does `nixpkgs.channels.default`!
+  #         A channel configuration must be declared for module context "${contextName}".
+  #       ''
+
   config = let
     # TODO: use lib.types.submodule to restrict what options
-    # TODO: can be given to pkgsrc
+    # TODO: can be given to `nixpkgs.channels.${moduleName}.${name}`
+    decl =
+      cfg.${contextName} or cfg.default;
+
     repos =
-      cfg
+      decl
       |> mapAttrs (
         name: args:
           assert args ? source
           || abort ''
-            ${./.}
-            `pkgsrc.${name} missing required attribute "source"`
+            ${toString ./.}
+            `nixpkgs.channels.${contextName}.${name} missing required attribute "source"`
           '';
-            args
-            |> flip removeAttrs ["source"]
+            ((removeAttrs args ["source"])
+              // {inherit system;})
             |> import args.source
+            |> lib.mkOverride 200
       );
   in {
     # NOTE: _module.args is a special option that allows us to
     # NOTE: set extend specialArgs from inside the modules.
     # "pkgs" is unique since the nix module system already handles it
-    _module.args =
-      removeAttrs repos ["pkgs"];
+    _module.args = removeAttrs repos ["pkgs"];
 
-    # nixpkgs =
-    #   lib.mkIf (cfg ? pkgs)
-    #   (let
-    #     pkgs = cfg.pkgs;
-    #   in
-    #     lib.mkForce (
-    #       (removeAttrs pkgs ["source"])
-    #       // {
-    #         flake.source = pkgs.source;
-    #       }
-    #     ));
+    nixpkgs =
+      if contextName == "hosts"
+      then {flake.source = lib.mkIf (decl ? pkgs) (lib.mkOverride 200 decl.pkgs.source);}
+      else {};
   };
 }

flake.lock

@@ -175,11 +175,11 @@
         "systems": "systems_2"
       },
       "locked": {
-        "lastModified": 1770950436,
-        "narHash": "sha256-+h5jrsIJBea5P+rAk4OqUpScqnHYQTvCRUhgGv/MX34=",
+        "lastModified": 1770975056,
+        "narHash": "sha256-ZXTz/P3zUbbM6lNXzt91u8EwfNqhXpYMu8+wvFZqQHE=",
         "owner": "cry128",
         "repo": "nt",
-        "rev": "8725f5079f8f27b3faafeff90e5fc075d55e7d0a",
+        "rev": "f42dcdd49a7921a7f433512e83d5f93696632412",
         "type": "github"
       },
       "original": {