Weird error when rebuilding

c00l_game_dev · July 2, 2025, 5:21pm

I’m working on my refactoring branch here: GitHub - Cool-Game-Dev/elysium at options-reformat

and whenever I try to rebuild using the following command: sudo nix build .#nixosConfigurations.Hydra.config.system.build.toplevel --extra-experimental-features pipe-operators (because nixos-rebuild doesn’t allow for the --extra-experimental-features flag) i get the following error:

error:
       … while calling the 'seq' builtin
         at /nix/store/h2bn031b0fj0ymv9v7bv5rcdjx58y2l9-source/lib/modules.nix:360:18:
          359|         options = checked options;
          360|         config = checked (removeAttrs config [ "_module" ]);
             |                  ^
          361|         _module = checked (config._module);

       … while calling the 'throw' builtin
         at /nix/store/h2bn031b0fj0ymv9v7bv5rcdjx58y2l9-source/lib/modules.nix:332:13:
          331|           else
          332|             throw baseMsg
             |             ^
          333|         else

       error: The option `default' does not exist. Definition values:
       - In `/nix/store/h2bn031b0fj0ymv9v7bv5rcdjx58y2l9-source/flake.nix': /nix/store/zyh2954p724f08p7lxakz86zi968p90s-source/nixos

When checking, /nix/store/h2bn031b0fj0ymv9v7bv5rcdjx58y2l9-source/flake.nix is nixpkgs, and /nix/store/zyh2954p724f08p7lxakz86zi968p90s-source/nixos is home-manager, both are fully up to date. I’m really not sure how to fix this, as it seems it’s an error in home-manager, but I’m not sure. Does anyone have ideas?

waffle8946 · July 2, 2025, 5:53pm

You missed a .default at the end of this line:

github.com/Cool-Game-Dev/elysium

flake.nix

5b47bb97f


      
                          inputs
                          outputs
                          lib
                          vauxhall
                          ;
                      };
                      modules = [
                        ./hosts/nixos/${host}
                        ./modules/core
                        ./modules/host-spec.nix
          							inputs.home-manager.nixosModules
                        inputs.sops-nix.nixosModules.sops
                      ];
                    };
                  })
                  |> builtins.listToAttrs;
              };
          }

c00l_game_dev · July 3, 2025, 3:16pm

Ah, that makes sense. Thanks for the help!

waffle8946 · July 4, 2025, 2:22pm

To provide a little more context about how I found it, maybe this helps debug in the future:

error: The option... messages are module system errors
The option ``default' does not exist indicates there’s something setting default = in a module, i.e. some incorrect attrset got put in modules/imports
The end of the error mentions essentially <home-manager/nixos/default.nix> hence I looked for something related to hm in your modules in flake.nix (since 90% of the time that’s where people put the NixOS module for HM)