feat: overhaul overlays module

flake.nix

@@ -60,19 +60,7 @@
     # Accessible through 'nix build', 'nix shell', etc
     packages = forAllSystems (system: import ./pkgs nixpkgs.legacyPackages.${system});
 
-    # This repo's overlay plus any other overlays you use
-    # If you want to use packages from flakes that are not nixpkgs (such as NUR), add their overlays here.\
-    overlays = {
-      default = import ./overlays inputs;
-      pkg-sets = (
-        final: prev: {
-          unstable = import inputs.unstable {system = final.system;};
-          trunk = import inputs.trunk {system = final.system;};
-        }
-      );
-      rust-overlay = rust-overlay.overlays.default;
-      vscode-extensions = nix-vscode-extensions.overlays.default;
-    };
+    overlays = import ./overlays {inherit inputs;};
 
     overlaysModule = {
       nixpkgs.overlays = builtins.attrValues self.overlays;

overlays/default.nix

@@ -1,13 +1,25 @@
-{
-  nixpkgs,
-  unstable,
-  ...
-}: let
-  inherit (nixpkgs.lib) composeManyExtensions;
-  inherit (builtins) attrNames readDir;
-  localOverlays =
-    map
-    (f: import (./default + "/${f}"))
-    (attrNames (readDir ./default));
-in
-  composeManyExtensions localOverlays
+{inputs, ...}: {
+  rust-overlay = inputs.rust-overlay.overlays.default;
+  vscode-extensions = inputs.nix-vscode-extensions.overlays.default;
+
+  # This one brings our custom packages from the 'pkgs' directory
+  additions = final: _prev: import ../pkgs final.pkgs;
+
+  # This one contains whatever you want to overlay
+  # You can change versions, add patches, set compilation flags, anything really.
+  # https://nixos.wiki/wiki/Overlays
+  modifications = final: prev: {
+    # example = prev.example.overrideAttrs (oldAttrs: rec {
+    # ...
+    # });
+  };
+
+  # When applied, the unstable nixpkgs set (declared in the flake inputs) will
+  # be accessible through 'pkgs.unstable'
+  unstable-packages = final: _prev: {
+    unstable = import inputs.unstable {
+      system = final.system;
+      config.allowUnfree = true;
+    };
+  };
+}