Migrate back to gccemacs with build cache

cachix/nix-community.nix

@@ -0,0 +1,8 @@
+{
+  nix = {
+    binaryCaches = [ "https://nix-community.cachix.org" ];
+    binaryCachePublicKeys = [
+      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+    ];
+  };
+}

configuration.nix

@@ -104,6 +104,8 @@
     ./modules/printing.nix
     ./modules/periodic.nix
     ./modules/power.nix
+    ./modules/cachix.nix
+    ./overlays/emacs-overlay.nix
   ];
 
 }

modules/cachix.nix

@@ -0,0 +1,13 @@
+# WARN: this file will get overwritten by $ cachix use <name>
+{ pkgs, lib, ... }:
+
+let
+  folder = ../cachix;
+  toImport = name: value: folder + ("/" + name);
+  filterCaches = key: value: value == "regular" && lib.hasSuffix ".nix" key;
+  imports = lib.mapAttrsToList toImport
+    (lib.filterAttrs filterCaches (builtins.readDir folder));
+in {
+  inherit imports;
+  nix.binaryCaches = [ "https://cache.nixos.org/" ];
+}

modules/software.nix

@@ -20,7 +20,7 @@
     haskellPackages.pandoc-citeproc
     # Text editors
     neovim
-    emacs
+    emacsGcc
     ripgrep
     fd
     clang
@@ -77,6 +77,8 @@
     ## Python
     nodePackages.pyright
     black
+    # Overlays
+    cachix
   ];
 
   # Fonts declaration

overlays/emacs-overlay.nix

@@ -0,0 +1,7 @@
+{
+  nixpkgs.overlays = [
+    (import (builtins.fetchTarball {
+      url = https://github.com/nix-community/emacs-overlay/archive/master.tar.gz;
+    }))
+  ];
+}