not really, it says
whuch means that it can find configuration.nix, but that file is expecting an inputs parameter that cannot be found. And indeed, the repo you’ve share previously has that. That’s a common convention (and only convention, nothing is forcing it and there are other ways) when using flakes, and looking deeper into your file, there is nixoslaptop-configs/configuration.nix at 7fa0e855fabece12b77ed3e604def3fceb846627 · enoren5/nixoslaptop-configs · GitHub which uses it.
Again, 3 venues are ahead, but this time more diffrerent than previously. You can either drop helix (possibly just for now). in this case remove thst line and remove inputs from nixoslaptop-configs/configuration.nix at 7fa0e855fabece12b77ed3e604def3fceb846627 · enoren5/nixoslaptop-configs · GitHub so that it reads { config, pkgs, lib, ... }:. After that run any of the 3 previous sets of commands.
You can return to flake config, effectively undoing what we done so far. This means recreating the flake.nix file that was deleted (isn’t that complex). This will get your packages upgraded now, but --upgrade-all to nixos-rebuild will not update it further. Upgrading is a simple command, but a different one.
Finally, we can try installing helix without flake, no idea how complex it. Especially as it’s available in nixpkgs by default, so you probably had a reason to pick a non-default one.
There’s nothing preventing us from removing helix temporarily and trying too re-add it later when we got nixos back into a sane state.