input nix unstable channel to flake

flake.nix

@@ -3,29 +3,35 @@
   description = "Dev Shell for dobutterfliescry.net";
 
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = {nixpkgs, ...}: let
+  outputs = {
+    nixpkgs,
+    nixpkgs-unstable,
+    ...
+  }: let
     system = "x86_64-linux";
+    pkgs = import nixpkgs {
+      inherit system;
+    };
+    pkgs-unstable = import nixpkgs-unstable {
+      inherit system;
+    };
   in {
-    devShells."${system}".default = let
-      pkgs = import nixpkgs {
-        inherit system;
-      };
-    in
-      pkgs.mkShell {
-        packages = with pkgs; [
-          # dev local server
-          simple-http-server
+    devShells."${system}".default = pkgs.mkShell {
+      packages = [
+        # dev local server
+        pkgs.simple-http-server-http-server
 
-          # css baking
-          sass
-          # image baking (from .svg)
-          imagemagick
-        ];
+        # css baking
+        pkgs-unstable.sass
+        # image baking (from .svg)
+        pkgs.imagemagick
+      ];
 
-        shell = "${pkgs.bash}/bin/bash";
-      };
+      shell = "${pkgs.bash}/bin/bash";
+    };
   };
 }