error: … in the right operand of the update (//) operator at /var/lib/nixbot/worktrees/1158-af746d39a306-300e138d/flake.nix:76:12: 75| } 76| // nixpkgs.lib.optionalAttrs pkgs.stdenv.isDarwin { | ^ 77| darwin-module = … while evaluating a branch condition at «github:NixOS/nixpkgs/35d3407a3816f3b341d8cf1d60abaf2b7b8166ac?narHash=sha256-BoYPdqk6jlKXy%2BDyUzyGV/CtRGfAhk2MmIgBhsemTGI%3D»/lib/attrsets.nix:1482:29: 1481| */ 1482| optionalAttrs = cond: as: if cond then as else { }; | ^ 1483| (stack trace truncated; use '--show-trace' to show the full, detailed trace) error: Nixpkgs 26.11 has dropped support for x86_64-darwin. The 26.05 stable branch still supports x86_64-darwin, and will receive security fixes until the end of 2026. If you use channels, you can switch to 26.05 as follows: $ sudo nix-channel --add https://nixos.org/channels/nixpkgs-26.05-darwin nixpkgs $ sudo nix-channel --update If this doesn’t work, you may need to run: # Lack of sudo is deliberate: $ nix-channel --remove nixpkgs If you use flakes, switch your flake input: inputs.nixpkgs = { url = "github:NixOS/nixpkgs/nixpkgs-26.05-darwin"; }; See the release notes for more information and alternatives: https://nixos.org/manual/nixpkgs/unstable/release-notes#x86_64-darwin-26.11