1error:2 … while evaluating a branch condition3 at «string»:25:5:4 24| v:5 25| if !builtins.isAttrs v || isDrv v then6 | ^7 26| v89 … in the left operand of the OR (||) operator10 at «string»:25:28:11 24| v:12 25| if !builtins.isAttrs v || isDrv v then13 | ^14 26| v1516 … while evaluating definitions from `/nix/store/9iv83r72z5xwgylkwms1qip1ijnr6jqs-source/modules/transposition.nix':1718 … while evaluating definitions from `/nix/store/j4vh379g10m1d797v5w0n83x4kffcxnr-source/flake.nix, via option perSystem':1920 … while evaluating definitions from `/nix/store/9iv83r72z5xwgylkwms1qip1ijnr6jqs-source/modules/transposition.nix':2122 … while evaluating definitions from `/nix/store/18kqjlbmkk4a44r0hqa7x3d5h4yhmv1w-source/nix/flake-module.nix':2324 … while evaluating the option `perSystem.x86_64-darwin.process-compose.dev.outputs.package':2526 … while evaluating definitions from `/nix/store/18kqjlbmkk4a44r0hqa7x3d5h4yhmv1w-source/nix/process-compose':2728 … while evaluating the module argument `pkgs' in "/nix/store/18kqjlbmkk4a44r0hqa7x3d5h4yhmv1w-source/nix/process-compose":2930 … while evaluating the module argument `pkgs' in ":anon-11: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/9iv83r72z5xwgylkwms1qip1ijnr6jqs-source/modules/transposition.nix':3536 … while evaluating definitions from `/nix/store/j4vh379g10m1d797v5w0n83x4kffcxnr-source/flake.nix, via option perSystem':3738 … while evaluating definitions from `/nix/store/9iv83r72z5xwgylkwms1qip1ijnr6jqs-source/modules/transposition.nix':3940 … while evaluating definitions from `/nix/store/j4vh379g10m1d797v5w0n83x4kffcxnr-source/nix/devShells/flake-module.nix, via option perSystem':4142 … while evaluating the module argument `pkgs' in ":anon-14:anon-1":4344 … noting that argument `pkgs` is not externally provided, so querying `_module.args` instead, requiring `config`4546 … while evaluating definitions from `/nix/store/j4vh379g10m1d797v5w0n83x4kffcxnr-source/flake.nix, via option perSystem':4748 (stack trace truncated; use '--show-trace' to show the full, detailed trace)4950 error: Nixpkgs 26.11 has dropped support for x86_64-darwin.5152 The 26.05 stable branch still supports x86_64-darwin, and will53 receive security fixes until the end of 2026. If you use channels,54 you can switch to 26.05 as follows:5556 $ sudo nix-channel --add https://nixos.org/channels/nixpkgs-26.05-darwin nixpkgs57 $ sudo nix-channel --update5859 If this doesn’t work, you may need to run:6061 # Lack of sudo is deliberate:62 $ nix-channel --remove nixpkgs6364 If you use flakes, switch your flake input:6566 inputs.nixpkgs = {67 url = "github:NixOS/nixpkgs/nixpkgs-26.05-darwin";68 };6970 See the release notes for more information and alternatives:7172 https://nixos.org/manual/nixpkgs/unstable/release-notes#x86_64-darwin-26.11