i cried

cerulean/nexus/nexus.nix

@@ -197,8 +197,8 @@ in {
               inherit root base;
               inherit (node) system;
               _cerulean = {
-                inherit inputs userArgs;
-                args = ceruleanArgs;
+                inherit inputs userArgs ceruleanArgs;
+                specialArgs = userArgs // ceruleanArgs;
               };
             };
             specialArgs = assert (userArgs
@@ -209,7 +209,7 @@ in {
                   `specialArgs` are like super important to Cerulean my love... </3
                   But `args.${argName}` is a reserved argument name :(
                 ''));
-              userArgs // ceruleanArgs;
+              ceruleanArgs._cerulean.specialArgs;
           in
             lib.nixosSystem {
               inherit (node) system;

cerulean/nixos/home-manager.nix

@@ -25,15 +25,16 @@
     pathExists
     ;
 in {
-  config = {
   home-manager = {
     users =
       config.users.users
       |> attrNames
       |> filter (x: pathExists (root + "/homes/${x}"))
-        |> (x: lib.genAttrs x (y: import (root + "/homes/${y}")));
+      |> (x:
+        lib.genAttrs x (y:
+          import (root + "/homes/${y}")));
 
-      extraSpecialArgs = _cerulean.args;
+    extraSpecialArgs = _cerulean.specialArgs;
     sharedModules = [
       # user configuration
       (import (root + "/nixpkgs.nix"))
@@ -41,5 +42,4 @@ in {
       (import ./nixpkgs.nix (args // {contextName = "homes";}))
     ];
   };
-  };
 }

cerulean/nixos/nixpkgs.nix

@@ -52,6 +52,7 @@ in {
   config = let
     repos =
       cfg
+      |> (xs: removeAttrs xs ["default"])
       |> mapAttrs (
         name: args:
           lib.mkForce (
@@ -59,28 +60,29 @@ in {
             || abort ''
               `nixpkgs.channels.${name}` missing required attribute "source"
             '';
-              ((removeAttrs args ["source"])
-                // {inherit system;})
-              |> import args.source
+              import args.source ({inherit system;} // (removeAttrs args ["source"]))
           )
       );
-  in {
-    # NOTE: _module.args is a special option that allows us to
-    # NOTE: set extend specialArgs from inside the modules.
-    _module.args = repos;
 
-    nixpkgs = let
     # XXX: TODO: would it work to use `base` instead of having default?
     defaultPkgs =
       cfg.default or (throw ''
         Your `nixpkgs.nix` file does not declare a default package source.
         Ensure you set `nixpkgs.channels.*.default = ...;`
       '');
-    in
+  in {
+    # NOTE: _module.args is a special option that allows us to
+    # NOTE: set extend specialArgs from inside the modules.
+    _module.args = repos;
+
+    nixpkgs =
       if contextName == "hosts"
-      then {
-        flake.source = lib.mkOverride 200 defaultPkgs.source;
-        config = lib.mkOverride 200 defaultPkgs.config;
+      then
+        # DEBUG: defaultPkgs
+        {
+          flake.source = lib.mkOverride 200 (defaultPkgs.source or null);
+          overlays = lib.mkOverride 200 (defaultPkgs.overlays or {});
+          config = lib.mkOverride 200 (defaultPkgs.config or {});
         }
       else if contextName == "homes"
       then {