flake: add option to install packages from nixos-unstable

flake.lock

@@ -57,7 +57,25 @@
     "root": {
       "inputs": {
         "home": "home",
-        "nixpkgs": "nixpkgs_2"
+        "nixpkgs": "nixpkgs_2",
+        "unstable": "unstable"
+      }
+    },
+    "unstable": {
+      "info": {
+        "lastModified": 1591465133,
+        "narHash": "sha256-HdXyiHl8TumxQZhs2/DCSnqbi1GnvqXaZlsJneGf0g0="
+      },
+      "locked": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "029a5de08390bb03c3f44230b064fd1850c6658a",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
       }
     }
   },

flake.nix

@@ -2,9 +2,10 @@
   description = "A highly structured configuration database.";
 
   inputs.nixpkgs.url = "nixpkgs/release-20.03";
+  inputs.unstable.url = "nixpkgs/nixos-unstable";
   inputs.home.url = "github:rycee/home-manager/bqv-flakes";
 
-  outputs = inputs@{ self, home, nixpkgs }:
+  outputs = inputs@{ self, home, nixpkgs, unstable }:
     let
       inherit (builtins) listToAttrs baseNameOf attrNames attrValues readDir;
       inherit (nixpkgs.lib) removeSuffix;
@@ -22,21 +23,26 @@
           value = import path;
         });
 
-      pkgs = import nixpkgs {
+      pkgImport = pkgs:
+        import pkgs {
           inherit system;
           overlays = attrValues self.overlays;
           config = { allowUnfree = true; };
         };
 
+      pkgs = pkgImport nixpkgs;
+
+      unstablePkgs = pkgImport unstable;
+
     in {
-      nixosConfigurations =
+      nixosConfigurations = let
-        let configs = import ./hosts (inputs // { inherit system pkgs; });
+        configs =
+          import ./hosts (inputs // { inherit system pkgs unstablePkgs; });
       in configs;
 
       overlay = import ./pkgs;
 
-      overlays =
+      overlays = let
-        let
         overlayDir = ./overlays;
         fullPath = name: overlayDir + "/${name}";
         overlayPaths = map fullPath (attrNames (readDir overlayDir));

hosts/default.nix

@@ -1,4 +1,4 @@
-inputs@{ home, nixpkgs, self, pkgs, system, ... }:
+inputs@{ home, nixpkgs, unstablePkgs, self, pkgs, system, ... }:
 let
   inherit (nixpkgs) lib;
 
@@ -12,7 +12,10 @@ let
     lib.nixosSystem {
       inherit system;
 
-      specialArgs.usr = { inherit utils; };
+      specialArgs = {
+        inherit unstablePkgs;
+        usr = { inherit utils; };
+      };
 
       modules = let
         inherit (home.nixosModules) home-manager;

profiles/graphical/qutebrowser/default.nix

@@ -1,10 +1,11 @@
-{ pkgs, ... }:
+{ unstablePkgs, ... }:
 let inherit (builtins) readFile;
 in {
   sound.enable = true;
 
   environment = {
-    etc."xdg/qutebrowser/config.py".text = let mpv = "${pkgs.mpv}/bin/mpv";
+    etc."xdg/qutebrowser/config.py".text =
+      let mpv = "${unstablePkgs.mpv}/bin/mpv";
       in ''
         ${readFile ./config.py}
 
@@ -14,6 +15,6 @@ in {
 
     sessionVariables.BROWSER = "qute";
 
-    systemPackages = with pkgs; [ qute qutebrowser mpv youtubeDL ];
+    systemPackages = with unstablePkgs; [ qute qutebrowser mpv youtubeDL ];
   };
 }