error: … while evaluating a branch condition at «string»:25:5: 24| v: 25| if !builtins.isAttrs v || isDrv v then | ^ 26| v … in the left operand of the OR (||) operator at «string»:25:28: 24| v: 25| if !builtins.isAttrs v || isDrv v then | ^ 26| v … while evaluating the option `system.build.toplevel': … while evaluating definitions from `/nix/store/8ak04fk7vigs495sxhxshyf7b9mlcmgb-source/nixos/modules/system/activation/top-level.nix': … while evaluating the option `warnings': … while evaluating definitions from `/nix/store/8ak04fk7vigs495sxhxshyf7b9mlcmgb-source/nixos/modules/system/boot/systemd.nix': … while evaluating the option `systemd.services.pinchflat.serviceConfig': … while evaluating definitions from `/nix/store/8ak04fk7vigs495sxhxshyf7b9mlcmgb-source/nixos/modules/services/misc/pinchflat.nix': (stack trace truncated; use '--show-trace' to show the full, detailed trace) error: Refusing to evaluate package 'pinchflat-2025.9.26' in /nix/store/8ak04fk7vigs495sxhxshyf7b9mlcmgb-source/pkgs/by-name/pi/pinchflat/package.nix:85 because it is marked as insecure Known issues: - multiple CVEs in dependencies. consider `pinchflat-ngx` fork as an alternative You can install it anyway by allowing this package, using the following methods: a) To temporarily allow all insecure packages, you can use an environment variable for a single invocation of the nix tools: $ export NIXPKGS_ALLOW_INSECURE=1 Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake, then pass `--impure` in order to allow use of environment variables. b) for `nixos-rebuild` you can add ‘pinchflat-2025.9.26’ to `nixpkgs.config.permittedInsecurePackages` in the configuration.nix, like so: { nixpkgs.config.permittedInsecurePackages = [ "pinchflat-2025.9.26" ]; } c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add ‘pinchflat-2025.9.26’ to `permittedInsecurePackages` in ~/.config/nixpkgs/config.nix, like so: { permittedInsecurePackages = [ "pinchflat-2025.9.26" ]; }