error:
       … while calling the 'seq' builtin
         at /nix/store/cncbwybi5fswwjkg9c76cgwm0bh6wsr9-source/lib/modules.nix:402:18:
          401|         options = checked options;
          402|         config = checked (removeAttrs config [ "_module" ]);
             |                  ^
          403|         _module = checked (config._module);

       … while evaluating a branch condition
         at /nix/store/cncbwybi5fswwjkg9c76cgwm0bh6wsr9-source/lib/modules.nix:305:9:
          304|       checkUnmatched =
          305|         if config._module.check && config._module.freeformType == null && merged.unmatchedDefns != [ ] then
             |         ^
          306|           let

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: undefined variable 'import-tree'
       at /nix/store/55kkrag72bfv79hgkd2dx6gc8q8q5g8z-source/Droidnix/generated/hosts/traveldroid/traveldroid.nix:12:27:
           11|   ]
           12|   ++ builtins.attrValues (import-tree ./generated/modules)
             |                           ^
           13|   ++ [
Command 'nix --extra-experimental-features 'nix-command flakes' build --print-out-paths '.#nixosConfigurations."traveldroid".config.system.build.nixos-rebuild' --no-link' returned non-zero exit status 1.