1error:2 … while evaluating the attribute 'optionalValue.value'3 at «git+https://github.com/NixOS/nixpkgs?ref=nixpkgs-unstable&rev=3d8f0f3f72a6cd4d93d0ad13203f2ea1cb7e1456&shallow=1»/lib/modules.nix:1330:5:4 1329|5 1330| optionalValue = if isDefined then { value = mergedValue; } else { };6 | ^7 1331| };89 … while evaluating a branch condition10 at «git+https://github.com/NixOS/nixpkgs?ref=nixpkgs-unstable&rev=3d8f0f3f72a6cd4d93d0ad13203f2ea1cb7e1456&shallow=1»/lib/modules.nix:1330:21:11 1329|12 1330| optionalValue = if isDefined then { value = mergedValue; } else { };13 | ^14 1331| };1516 … while evaluating definitions from `/nix/store/xfg4bws749i95jvnxhymxmfwailzk38q-source/modules/transposition.nix':1718 … while evaluating definitions from `/nix/store/jhr81pkrlv465sxybzr0czcyv1y6fqqs-source/checks/flake-module.nix, via option perSystem':1920 … while evaluating definitions from `/nix/store/jam81gdfp0984mmjnf4hmgzys9y8v9vf-source/flakeModules/clan.nix':2122 … while evaluating definitions from `/nix/store/jam81gdfp0984mmjnf4hmgzys9y8v9vf-source/modules/clan/module.nix':2324 (stack trace truncated; use '--show-trace' to show the full, detailed trace)2526 error:27 nix-darwin now uses release branches that correspond to Nixpkgs releases.28 The nix-darwin and Nixpkgs branches in use must match, but you are currently29 using nix-darwin 26.11 with Nixpkgs 26.05.3031 On macOS, you should use either the `nixpkgs-unstable` or32 `nixpkgs-YY.MM-darwin` branches of Nixpkgs. These correspond to the33 `master` and `nix-darwin-YY.MM` branches of nix-darwin, respectively. Check34 <https://status.nixos.org/> for the currently supported Nixpkgs releases.3536 If you’re using flakes, make sure your inputs look like this:3738 inputs = {39 nixpkgs.url = "github:NixOS/nixpkgs/NIXPKGS-BRANCH";40 nix-darwin.url = "github:nix-darwin/nix-darwin/NIX-DARWIN-BRANCH";41 nix-darwin.inputs.nixpkgs.follows = "nixpkgs";42 # …43 };4445 If you’re using channels, you can check your current channels with:4647 $ sudo nix-channel --list48 nixpkgs https://nixos.org/channels/NIXPKGS-BRANCH49 darwin https://github.com/nix-darwin/nix-darwin/archive/NIX-DARWIN-BRANCH.tar.gz50 …51 $ nix-channel --list52 …5354 If `darwin` or `nixpkgs` are present in `nix-channel --list` (without55 `sudo`), you should delete them with `nix-channel --remove NAME`. These can56 contribute to version mismatch problems.5758 You can then fix your channels like this:5960 $ sudo nix-channel --add https://nixos.org/channels/NIXPKGS-BRANCH nixpkgs61 $ sudo nix-channel --add https://github.com/nix-darwin/nix-darwin/archive/NIX-DARWIN-BRANCH.tar.gz darwin62 $ sudo nix-channel --update6364 After that, activating your system again should work correctly. If it65 doesn’t, please open an issue at66 <https://github.com/nix-darwin/nix-darwin/issues/new> and include as much67 information as possible.