Add devshell

flake.nix

@@ -68,6 +68,20 @@
 			}
 		);
 
+		devShell = (flake-utils.lib.eachSystemMap flake-utils.lib.allSystems (system: let
+			pkgs = import nixunstable { inherit system overlays; };
+		in pkgs.mkShell {
+			buildInputs = with pkgs; [
+				bashInteractive
+				curl
+				gzip
+				inject
+				sudo
+				tar
+				xonsh
+			];
+		}));
+
 		overlays = { default = local_overlay; };
 		modules = (import ./modules-all {}) //
 		          (import ./modules-linux {}) //

overlays/default.nix

@@ -73,6 +73,7 @@ in rec {
 	hms = prev.callPackage ./hms.nix {
 		pkgs = final.pkgs;
 	};
+	inject = prev.callPackage ./inject.nix { inherit (final) pkgs; };
 	setup-ssh = prev.callPackage ./setup-ssh.nix {
 		pkgs = final.pkgs;
 	};

overlays/inject.nix

@@ -0,0 +1,3 @@
+{ pkgs, ... }:
+
+pkgs.writeShellScriptBin "inject-nixos-config" (builtins.readFile ./inject.sh)