flake: move 'nixosConfigurations' to 'flake/'

I don't get an error during `nix flake check` anymore.

This reverts commit 8a556585af.

.envrc

@@ -1,9 +1,10 @@
-use_flake() {
-  watch_file flake.nix
-  watch_file flake.lock
-  eval "$(nix print-dev-env)"
-}
+if ! has nix_direnv_version || ! nix_direnv_version 2.2.1; then
+    source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.2.1/direnvrc" "sha256-zelF0vLbEl5uaqrfIzbgNzJWGmLzCmYAkInj/LNxvKs="
+fi
 
-ulimit -s unlimited # Bypass current bug in `nix` flakes evaluation
 use flake
+
+watch_file ./flake/checks.nix
+watch_file ./flake/dev-shells.nix
+
 eval "$shellHooks"

flake.nix

@@ -67,9 +67,12 @@
     , pre-commit-hooks
     }:
     let
+      inherit (self) lib;
+
       inherit (futils.lib) eachSystem system;
 
       mySystems = [
+        system.aarch64-darwin
         system.aarch64-linux
         system.x86_64-darwin
         system.x86_64-linux
@@ -77,87 +80,20 @@
 
       eachMySystem = eachSystem mySystems;
 
-      lib = nixpkgs.lib.extend (self: super: {
-        my = import ./lib { inherit inputs; pkgs = nixpkgs; lib = self; };
-      });
-
-      defaultModules = [
-        ({ ... }: {
-          # Let 'nixos-version --json' know about the Git revision
-          system.configurationRevision = self.rev or "dirty";
-        })
-        {
-          nixpkgs.overlays = (lib.attrValues self.overlays) ++ [
-            nur.overlay
-          ];
-        }
-        # Include generic settings
-        ./modules
-        # Include bundles of settings
-        ./profiles
-      ];
-
-      buildHost = name: system: lib.nixosSystem {
-        inherit system;
-        modules = defaultModules ++ [
-          (./. + "/machines/${name}")
-        ];
-        specialArgs = {
-          # Use my extended lib in NixOS configuration
-          inherit lib;
-          # Inject inputs to use them in global registry
-          inherit inputs;
-        };
-      };
     in
     eachMySystem
       (system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
-      in
       rec {
         apps = {
           diff-flake = futils.lib.mkApp { drv = packages.diff-flake; };
           default = apps.diff-flake;
         };
 
-        checks = {
-          pre-commit = pre-commit-hooks.lib.${system}.run {
-            src = ./.;
+        checks = import ./flake/checks.nix inputs system;
 
-            hooks = {
-              nixpkgs-fmt = {
-                enable = true;
-              };
+        devShells = import ./flake/dev-shells.nix inputs system;
 
-              shellcheck = {
-                enable = true;
-              };
-            };
-          };
-        };
-
-        devShells = {
-          default = pkgs.mkShell {
-            name = "NixOS-config";
-
-            nativeBuildInputs = with pkgs; [
-              gitAndTools.pre-commit
-              nixpkgs-fmt
-            ];
-
-            inherit (self.checks.${system}.pre-commit) shellHook;
-          };
-        };
-
-        packages =
-          let
-            inherit (futils.lib) filterPackages flattenTree;
-            packages = import ./pkgs { inherit pkgs; };
-            flattenedPackages = flattenTree packages;
-            finalPackages = filterPackages system flattenedPackages;
-          in
-          finalPackages;
+        packages = import ./flake/packages.nix inputs system;
 
         # Work-around for https://github.com/nix-community/home-manager/issues/3075
         legacyPackages = {
@@ -196,16 +132,10 @@
           };
         };
       }) // {
-      overlays = import ./overlays // {
-        lib = final: prev: { inherit lib; };
-        pkgs = final: prev: {
-          ambroisie = prev.recurseIntoAttrs (import ./pkgs { pkgs = prev; });
-        };
-      };
+      lib = import ./flake/lib.nix inputs;
 
-      nixosConfigurations = lib.mapAttrs buildHost {
-        aramis = "x86_64-linux";
-        porthos = "x86_64-linux";
-      };
+      overlays = import ./flake/overlays.nix inputs;
+
+      nixosConfigurations = import ./flake/nixos.nix inputs;
     };
 }

flake/checks.nix

@@ -0,0 +1,17 @@
+{ self, pre-commit-hooks, ... }:
+system:
+{
+  pre-commit = pre-commit-hooks.lib.${system}.run {
+    src = self;
+
+    hooks = {
+      nixpkgs-fmt = {
+        enable = true;
+      };
+
+      shellcheck = {
+        enable = true;
+      };
+    };
+  };
+}

flake/dev-shells.nix

@@ -0,0 +1,17 @@
+{ self, nixpkgs, ... }:
+system:
+let
+  pkgs = nixpkgs.legacyPackages.${system};
+in
+{
+  default = pkgs.mkShell {
+    name = "NixOS-config";
+
+    nativeBuildInputs = with pkgs; [
+      gitAndTools.pre-commit
+      nixpkgs-fmt
+    ];
+
+    inherit (self.checks.${system}.pre-commit) shellHook;
+  };
+}

flake/lib.nix

@@ -0,0 +1,7 @@
+{ self, nixpkgs, ... } @ inputs:
+let
+  lib = nixpkgs.lib.extend (final: _: {
+    my = import "${self}/lib" { inherit inputs; pkgs = nixpkgs; lib = final; };
+  });
+in
+lib

flake/nixos.nix

@@ -0,0 +1,37 @@
+{ self, nixpkgs, nur, ... } @ inputs:
+let
+  inherit (self) lib;
+
+  defaultModules = [
+    ({ ... }: {
+      # Let 'nixos-version --json' know about the Git revision
+      system.configurationRevision = self.rev or "dirty";
+    })
+    {
+      nixpkgs.overlays = (lib.attrValues self.overlays) ++ [
+        nur.overlay
+      ];
+    }
+    # Include generic settings
+    "${self}/modules"
+    # Include bundles of settings
+    "${self}/profiles"
+  ];
+
+  buildHost = name: system: lib.nixosSystem {
+    inherit system;
+    modules = defaultModules ++ [
+      "${self}/machines/${name}"
+    ];
+    specialArgs = {
+      # Use my extended lib in NixOS configuration
+      inherit lib;
+      # Inject inputs to use them in global registry
+      inherit inputs;
+    };
+  };
+in
+lib.mapAttrs buildHost {
+  aramis = "x86_64-linux";
+  porthos = "x86_64-linux";
+}

flake/overlays.nix

@@ -0,0 +1,16 @@
+{ self, ... }:
+
+let
+  default-overlays = import "${self}/overlays";
+
+  additional-overlays = {
+    # Expose my expanded library
+    lib = final: prev: { inherit (self) lib; };
+
+    # Expose my custom packages
+    pkgs = final: prev: {
+      ambroisie = prev.recurseIntoAttrs (import "${self}/pkgs" { pkgs = prev; });
+    };
+  };
+in
+default-overlays // additional-overlays

flake/packages.nix

@@ -0,0 +1,10 @@
+{ self, futils, nixpkgs, ... }:
+system:
+let
+  inherit (futils.lib) filterPackages flattenTree;
+  pkgs = nixpkgs.legacyPackages.${system};
+  packages = import "${self}/pkgs" { inherit pkgs; };
+  flattenedPackages = flattenTree packages;
+  finalPackages = filterPackages system flattenedPackages;
+in
+finalPackages

pkgs/ff2mpv-go/default.nix

@@ -9,7 +9,7 @@ buildGoModule rec {
     sha256 = "sha256-e/AuOA3isFTyBf97Zwtr16yo49UdYzvktV5PKB/eH/s=";
   };
 
-  vendorSha256 = "sha256-pQpattmS9VmO3ZIQUFn66az8GSmB4IvYhTTCFn6SUmo=";
+  vendorHash = null;
 
   postPatch = ''
     sed -i -e 's,"mpv","${mpv}/bin/mpv",' ff2mpv.go