26.05: source Lix from nixpkgs, fix disko btrfs label

nixos-26.05 removed lix_2_93, which the lix-module release-2.93 branch
hard-pins via lixFromNixpkgs (no 2.94 module release exists yet). Drop
the lix-module input and set nix.package = pkgs.lix, which is Lix 2.94.2
on 26.05 — so we stay on Lix, just sourced from nixpkgs.

Also: newer disko dropped the btrfs `label` option; pass -L nixos via
extraArgs instead so the impermanence rollback still finds the "nixos"
label.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

flake.lock

@@ -125,39 +125,6 @@
         "type": "github"
       }
     },
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "flakey-profile": {
-      "locked": {
-        "lastModified": 1712898590,
-        "narHash": "sha256-FhGIEU93VHAChKEXx905TSiPZKga69bWl1VB37FK//I=",
-        "owner": "lf-",
-        "repo": "flakey-profile",
-        "rev": "243c903fd8eadc0f63d205665a92d4df91d42d9d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "lf-",
-        "repo": "flakey-profile",
-        "type": "github"
-      }
-    },
     "flox": {
       "inputs": {
         "crane": "crane",
@@ -288,44 +255,6 @@
         "type": "github"
       }
     },
-    "lix": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1768477252,
-        "narHash": "sha256-RgET5pILoiG+3GnDpgfUEA4y8ISfZe6SB+geE+8U76Y=",
-        "rev": "fbe811e94e9c4efc9b9c283fe2fbb3aeff50fca7",
-        "type": "tarball",
-        "url": "https://git.lix.systems/api/v1/repos/lix-project/lix/archive/fbe811e94e9c4efc9b9c283fe2fbb3aeff50fca7.tar.gz?rev=fbe811e94e9c4efc9b9c283fe2fbb3aeff50fca7"
-      },
-      "original": {
-        "type": "tarball",
-        "url": "https://git.lix.systems/lix-project/lix/archive/release-2.93.tar.gz"
-      }
-    },
-    "lix-module": {
-      "inputs": {
-        "flake-utils": "flake-utils",
-        "flakey-profile": "flakey-profile",
-        "lix": "lix",
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1756125859,
-        "narHash": "sha256-6a+PWILmqHCs9B5eIBLg6HSZ8jYweZpgOWO8FlyVwYI=",
-        "ref": "release-2.93",
-        "rev": "d3292125035b04df00d01549a26e948631fabe1e",
-        "revCount": 156,
-        "type": "git",
-        "url": "https://git.lix.systems/lix-project/nixos-module"
-      },
-      "original": {
-        "ref": "release-2.93",
-        "type": "git",
-        "url": "https://git.lix.systems/lix-project/nixos-module"
-      }
-    },
     "nix-flatpak": {
       "locked": {
         "lastModified": 1767983141,
@@ -380,16 +309,16 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1769741972,
+        "lastModified": 1787753485,
-        "narHash": "sha256-RxSg1EioTWNpoLaykiT1UQKTo/K0PPdLqCyQgNjNqWs=",
+        "narHash": "sha256-BZWCi9ZRJiARTuKTbbtvFTj7t1TK4G3UEckT3HyNfRg=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "63590ac958a8af30ebd52c7a0309d8c52a94dd77",
+        "rev": "062346a6d85bc4b49dfaa61c986e9c5be21217d1",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-25.11",
+        "ref": "nixos-26.05",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -467,7 +396,6 @@
         "flox": "flox",
         "impermanence": "impermanence",
         "lanzaboote": "lanzaboote",
-        "lix-module": "lix-module",
         "nix-flatpak": "nix-flatpak",
         "nix-index-database": "nix-index-database",
         "nixpkgs": "nixpkgs_2",
@@ -511,21 +439,6 @@
         "repo": "rust-overlay",
         "type": "github"
       }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -20,8 +20,6 @@
       url = "github:nix-community/NUR";
       inputs.nixpkgs.follows = "nixpkgs";
     };
-    lix-module.url = "git+https://git.lix.systems/lix-project/nixos-module?ref=release-2.93";
-    lix-module.inputs.nixpkgs.follows = "nixpkgs";
     lanzaboote.url = "github:nix-community/lanzaboote";
     lanzaboote.inputs.nixpkgs.follows = "nixpkgs";
     flox.url = "github:flox/flox";

modules/profile/nanuqsaurus.nix

@@ -1,8 +1,11 @@
 { inputs }:
-{ ... }:
+{ pkgs, ... }:
 {
+  # Use Lix from nixpkgs (2.94.x on nixos-26.05). The lix-module's
+  # lixFromNixpkgs still pins lix_2_93, which nixos-26.05 removed.
+  nix.package = pkgs.lix;
+
   imports = [
-    inputs.lix-module.nixosModules.lixFromNixpkgs
     inputs.nix-index-database.nixosModules.nix-index
     inputs.nix-flatpak.nixosModules.nix-flatpak
     inputs.impermanence.nixosModules.impermanence

modules/system/disko-btrfs.nix

@@ -26,8 +26,9 @@
             size = "100%";
             content = {
               type = "btrfs";
-              extraArgs = [ "-f" ];
+              # Filesystem label "nixos" is required by the impermanence rollback
-              label = "nixos";
+              # logic. Newer disko dropped the `label` option; pass it to mkfs.btrfs.
+              extraArgs = [ "-f" "-L" "nixos" ];
               subvolumes = {
                 root = {
                   mountpoint = "/";