From bfb6ef1d59338e07f94f395cc56c98c116987c3d Mon Sep 17 00:00:00 2001 From: danbst Date: Wed, 5 Jun 2019 02:50:49 +0300 Subject: [PATCH] module system: prettify a bit error when unique option defined twice The error can be reproduced like: ``` $ nix-instantiate ./nixos -A system --arg configuration ' { fileSystems."/".device = "nodev"; boot.loader.grub.devices = [ "nodev" ]; containers.t.config.imports = [ ]; }' ``` Previously error was: ``` error: The unique option `containers.t.networking.hostName' is defined multiple times, in `/nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos/modules/virtualisation/amazon-image.nix' and `module at /home/danbst/dev/nixpkgs/nixos/modules/virtualisation/containers.nix:470'. (use '--show-trace' to show detailed location information) ``` Now it is: ``` error: The unique option `containers.t.networking.hostName' is defined multiple times, in: - /nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos/modules/virtualisation/amazon-image.nix - module at /home/danbst/dev/nixpkgs/nixos/modules/virtualisation/containers.nix:470. (use '--show-trace' to show detailed location information) ``` Related: https://github.com/NixOS/nixpkgs/issues/15747 --- lib/options.nix | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/options.nix b/lib/options.nix index a16a980398d6..d2eae3ae3a98 100644 --- a/lib/options.nix +++ b/lib/options.nix @@ -101,7 +101,7 @@ rec { mergeOneOption = loc: defs: if defs == [] then abort "This case should never happen." else if length defs != 1 then - throw "The unique option `${showOption loc}' is defined multiple times, in ${showFiles (getFiles defs)}." + throw "The unique option `${showOption loc}' is defined multiple times, in:\n - ${concatStringsSep "\n - " (getFiles defs)}." else (head defs).value; /* "Merge" option definitions by checking that they all have the same value. */