1error:2 … while evaluating the attribute 'optionalValue.value'3 at «git+https://github.com/NixOS/nixpkgs?ref=nixos-unstable-small&rev=3d2613bc58a1f5b7805467a63a825e1d7bc9b7a9&shallow=1»/lib/modules.nix:1312:5:4 1311|5 1312| optionalValue = if isDefined then { value = mergedValue; } else { };6 | ^7 1313| };89 … while evaluating a branch condition10 at «git+https://github.com/NixOS/nixpkgs?ref=nixos-unstable-small&rev=3d2613bc58a1f5b7805467a63a825e1d7bc9b7a9&shallow=1»/lib/modules.nix:1312:21:11 1311|12 1312| optionalValue = if isDefined then { value = mergedValue; } else { };13 | ^14 1313| };1516 … while evaluating definitions from `/nix/store/xfg4bws749i95jvnxhymxmfwailzk38q-source/modules/transposition.nix':1718 … while evaluating the option `perSystem.x86_64-darwin.checks':1920 … while evaluating definitions from `/nix/store/2zlawpvcxq0n77s37xssyivvqywrhx3l-source/flake.nix, via option perSystem':2122 … while evaluating definitions from `/nix/store/xfg4bws749i95jvnxhymxmfwailzk38q-source/modules/transposition.nix':2324 … while evaluating definitions from `/nix/store/xfg4bws749i95jvnxhymxmfwailzk38q-source/modules/transposition.nix':2526 … while evaluating the option `perSystem.x86_64-darwin.packages':2728 … while evaluating definitions from `/nix/store/2zlawpvcxq0n77s37xssyivvqywrhx3l-source/vm/flake-module.nix, via option perSystem':2930 … while evaluating the module argument `pkgs' in ":anon-12:anon-1":3132 … noting that argument `pkgs` is not externally provided, so querying `_module.args` instead, requiring `config`3334 … while evaluating definitions from `/nix/store/xfg4bws749i95jvnxhymxmfwailzk38q-source/modules/transposition.nix':3536 (stack trace truncated; use '--show-trace' to show the full, detailed trace)3738 error: Nixpkgs 26.11 has dropped support for x86_64-darwin.3940 The 26.05 stable branch still supports x86_64-darwin, and will41 receive security fixes until the end of 2026. If you use channels,42 you can switch to 26.05 as follows:4344 $ sudo nix-channel --add https://nixos.org/channels/nixpkgs-26.05-darwin nixpkgs45 $ sudo nix-channel --update4647 If this doesn’t work, you may need to run:4849 # Lack of sudo is deliberate:50 $ nix-channel --remove nixpkgs5152 If you use flakes, switch your flake input:5354 inputs.nixpkgs = {55 url = "github:NixOS/nixpkgs/nixpkgs-26.05-darwin";56 };5758 See the release notes for more information and alternatives:5960 https://nixos.org/manual/nixpkgs/unstable/release-notes#x86_64-darwin-26.11