Use nix-fast-build from flake (it supports native attic pushing)

flake.lock

@@ -223,6 +223,27 @@
       }
     },
     "flake-parts_3": {
+      "inputs": {
+        "nixpkgs-lib": [
+          "nix-fast-build",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1722555600,
+        "narHash": "sha256-XOQkdLafnb/p9ij77byFQjDf5m5QYl9b2REiVClC+x4=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "8471fe90ad337a8074e957b69ca4d0089218391d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "flake-parts_4": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib_2"
       },
@@ -240,7 +261,7 @@
         "type": "github"
       }
     },
-    "flake-parts_4": {
+    "flake-parts_5": {
       "inputs": {
         "nixpkgs-lib": [
           "nixThePlanet",
@@ -398,7 +419,7 @@
     },
     "hercules-ci-effects": {
       "inputs": {
-        "flake-parts": "flake-parts_4",
+        "flake-parts": "flake-parts_5",
         "nixpkgs": "nixpkgs_6"
       },
       "locked": {
@@ -622,6 +643,28 @@
         "type": "github"
       }
     },
+    "nix-fast-build": {
+      "inputs": {
+        "flake-parts": "flake-parts_3",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "treefmt-nix": "treefmt-nix_2"
+      },
+      "locked": {
+        "lastModified": 1730278911,
+        "narHash": "sha256-CrbqsC+lEA3w6gLfpqfDMDEKoEta2sl4sbQK6Z/gXak=",
+        "owner": "Mic92",
+        "repo": "nix-fast-build",
+        "rev": "8e7c9d76979381441facb8888f21408312cf177a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Mic92",
+        "repo": "nix-fast-build",
+        "type": "github"
+      }
+    },
     "nix-formatter-pack": {
       "inputs": {
         "nixpkgs": [
@@ -712,7 +755,7 @@
     },
     "nixThePlanet": {
       "inputs": {
-        "flake-parts": "flake-parts_3",
+        "flake-parts": "flake-parts_4",
         "hercules-ci-effects": "hercules-ci-effects",
         "nixpkgs": [
           "nixpkgs"
@@ -1119,12 +1162,13 @@
         "lix-eval-jobs": "lix-eval-jobs",
         "lix-module": "lix-module",
         "mobile-nixos": "mobile-nixos",
+        "nix-fast-build": "nix-fast-build",
         "nix-on-droid": "nix-on-droid",
         "nixDarwin": "nixDarwin",
         "nixThePlanet": "nixThePlanet",
         "nixosHardware": "nixosHardware",
         "nixpkgs": "nixpkgs_7",
-        "treefmt-nix": "treefmt-nix_2",
+        "treefmt-nix": "treefmt-nix_3",
         "vscode-server": "vscode-server"
       }
     },
@@ -1254,6 +1298,27 @@
       }
     },
     "treefmt-nix_2": {
+      "inputs": {
+        "nixpkgs": [
+          "nix-fast-build",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1723808491,
+        "narHash": "sha256-rhis3qNuGmJmYC/okT7Dkc4M8CeUuRCSvW6kC2f3hBc=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "1d07739554fdc4f8481068f1b11d6ab4c1a4167a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    },
+    "treefmt-nix_3": {
       "inputs": {
         "nixpkgs": [
           "nixpkgs"

flake.nix

@@ -62,6 +62,10 @@
     };
     catppuccin.url = "github:catppuccin/nix";
     emacs-overlay.url = "github:nix-community/emacs-overlay";
+    nix-fast-build = {
+      url = "github:Mic92/nix-fast-build";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs =

modules/nix/default.nix

@@ -2,17 +2,23 @@
   config,
   lib,
   fleetFlake,
+  pkgs,
   ...
 }:
 {
   nixpkgs.overlays = [
     (final: _: {
+      nix-fast-build = fleetFlake.inputs.nix-fast-build.packages.${final.system}.nix-fast-build // {
+        nix = final.nix;
+      };
       nix-eval-job = fleetFlake.inputs.lix-eval-jobs.packages.${final.system}.nix-eval-jobs // {
         nix = final.nix;
       };
     })
   ];
 
+  environment.systemPackages = [ pkgs.nix-fast-build ];
+
   nix = {
     optimise.automatic = true;