konawall package removal, rustfmt override

overlays/default.nix

@@ -0,0 +1,35 @@
+{ sources, system ? builtins.currentSystem, ... }@args:
+
+let
+  overlay = self: super: {
+    nur = import sources.nur {
+      nurpkgs = self;
+      pkgs = self;
+    };
+    rustfmt = super.rustfmt.overrideAttrs ({ patches ? [], ... }: {
+      patches = patches ++ [
+          # Adds an option variant that merges all use statements into a single block.
+          # Taken from https://github.com/rust-lang/rustfmt/pull/4680
+          ./Implement-One-option-for-imports_granularity-4669.patch
+        ];
+      });
+      linuxPackagesFor = kernel: (super.linuxPackagesFor kernel).extend (_: ksuper: {
+        zfsUnstable = ksuper.zfsUnstable.overrideAttrs (old: { meta = old.meta // { broken = false; }; });
+      });
+    };
+    pkgs = import sources.nixpkgs {
+      overlays = [
+        (import (sources.arcexprs + "/overlay.nix"))
+        (import (sources.katexprs + "/overlay.nix"))
+        (import sources.emacs-overlay)
+        overlay
+      ];
+      config = {
+        allowUnfree = true;
+        permittedInsecurePackages = [
+          "ffmpeg-3.4.8"
+        ];
+      };
+    };
+in
+  pkgs