Use overlays system-wide

5 files changed, 19 insertions, 7 deletions

diff --git a/flake.nix b/flake.nix
index 21245bc..cbad259 100644
--- a/flake.nix
+++ b/flake.nix
@@ -13,9 +13,10 @@
     };
   };
 
-  outputs = { nixpkgs, home-manager, nix-darwin, ... }@inputs:
+  outputs = { self, nixpkgs, home-manager, nix-darwin, ... }@inputs:
     let
       args = {
+        inherit self;
         flakeInputs = inputs;
         metadata = nixpkgs.lib.importTOML ./metadata.toml;
       };
@@ -31,7 +32,6 @@
             ./hosts/muhammed/configuration.nix
             ./hosts/common.nix
             ./home
-            { nixpkgs.overlays = [ (import ./pkgs/overlay.nix) ]; }
             # FIXME: Get the following to work without nix-darwin bithcing about unused NixOS options.
             # ./lib
             # ./modules
@@ -49,7 +49,6 @@
             ./hosts/ahmed/configuration.nix
             ./hosts/common.nix
             ./home
-            { nixpkgs.overlays = [ (import ./pkgs/overlay.nix) ]; }
             ./lib
 	    ./modules
             ./services
diff --git a/home/default.nix b/home/default.nix
index f0aa53b..d10062b 100644
--- a/home/default.nix
+++ b/home/default.nix
@@ -1,4 +1,4 @@
-{ flakeInputs, metadata, ... }:
+{ self, flakeInputs, metadata, ... }:
 
 {
   # Use the flake input pkgs so Home Manager configuration can share overlays
@@ -7,7 +7,7 @@
 
   # Pass special arguments from flake.nix further down the chain. I really hate
   # this split module system.
-  home-manager.extraSpecialArgs = { inherit flakeInputs metadata; };
+  home-manager.extraSpecialArgs = { inherit self flakeInputs metadata; };
 
   # OKAY FUCK THIS SHIT. THERE IS ONE USER. IT IS ME. LINUS. I WILL ADD
   # MULTIUSER SUPPORT IF IT EVER BECOMES A REQUIREMENT.
diff --git a/hosts/common.nix b/hosts/common.nix
index 87c6b27..84d0354 100644
--- a/hosts/common.nix
+++ b/hosts/common.nix
@@ -1,11 +1,18 @@
 # Shared configuraion regardless of hosts.
 
-{ pkgs, ... }:
+{ pkgs, options, self, ... }:
 
 {
   # Enable de facto stable features.
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
+  # Use overlays from this repo for building system configuration as well as
+  # system-wide.
+  #
+  # See: https://nixos.wiki/wiki/Overlays#Using_nixpkgs.overlays_from_configuration.nix_as_.3Cnixpkgs-overlays.3E_in_your_NIX_PATH
+  nixpkgs.overlays = (import ../pkgs/overlays.nix);
+  nix.nixPath = options.nix.nixPath.default ++ [ "nixpkgs-overlays=${self}/pkgs/overlays.nix" ];
+
   # Set ZSH as the shell.
   # https://nixos.wiki/wiki/Command_Shell#Changing_default_shelltrue
   programs.zsh.enable = true;
diff --git a/pkgs/overlay.nix b/pkgs/overlay.nix
deleted file mode 100644
index 9e0a6c4..0000000
--- a/pkgs/overlay.nix
+++ /dev/null
@@ -1 +0,0 @@
-self: super: (import ./default.nix) super
diff --git a/pkgs/overlays.nix b/pkgs/overlays.nix
new file mode 100644
index 0000000..cbe2222
--- /dev/null
+++ b/pkgs/overlays.nix
@@ -0,0 +1,7 @@
+# Returns a list of overlays such that this file can be used for the value of
+# nixpkgs-overlays in NIX_PATH.
+#
+# See: hosts/common.nix
+# See: https://nixos.org/manual/nixpkgs/stable/#sec-overlays-lookup
+
+[ (self: super: (import ./default.nix) super) ]