From 0b83ab6bf1fba291bdd2df552a318582958fa82c Mon Sep 17 00:00:00 2001
From: Zhaofeng Li <hello@zhaofeng.li>
Date: Fri, 3 Dec 2021 09:33:11 -0800
Subject: [PATCH] flake.nix: Clean up, allow overriding pkgs

`outputs.overlays` is supposed to be an attribute set of overlays,
and `outputs.overlay` should contain a single overlay.
---
 flake.nix | 46 +++++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

diff --git a/flake.nix b/flake.nix
index a6d91b5..4b97efa 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,32 +9,24 @@
     };
   };
 
-  outputs = { self, nixpkgs, home-manager, flake-utils }:
-    {
-      overlays = import ./overlays;
-    } //
-    flake-utils.lib.eachSystem [
-      "aarch64-linux"
-      "i686-linux"
-    ]
-      (system:
-        let pkgs = import nixpkgs {
-          inherit system;
-          overlays = self.overlays;
-        }; in
-        rec {
-          lib = {
-            nix-on-droid = { config }: import ./modules {
-              inherit pkgs config;
-              isFlake = true;
-              home-manager = (import home-manager { });
-            };
-          };
+  outputs = { self, nixpkgs, home-manager, flake-utils }: let
+    supportedSystems = [ "aarch64-linux" "i686-linux" ];
+  in flake-utils.lib.eachSystem supportedSystems (system: let
+    defaultPkgs = import nixpkgs {
+      inherit system;
+      overlays = [ self.overlay ];
+    };
+  in rec {
+    lib.nix-on-droid = { pkgs ? defaultPkgs, config }: import ./modules {
+      inherit pkgs home-manager config;
+      isFlake = true;
+    };
 
-          apps.nix-on-droid = flake-utils.lib.mkApp {
-            drv = (pkgs.callPackage ./nix-on-droid { });
-          };
-          defaultApp = apps.nix-on-droid;
-        }
-      );
+    apps.nix-on-droid = flake-utils.lib.mkApp {
+      drv = (defaultPkgs.callPackage ./nix-on-droid { });
+    };
+    defaultApp = apps.nix-on-droid;
+  }) // {
+    overlay = nixpkgs.lib.composeManyExtensions (import ./overlays);
+  };
 }