EtaReduce results in failing flake check

[pinpox]

The following line in a flake gives me an error:

      overlays.default = final: prev: (import ./overlays inputs) final prev;

Possible η-reduction of argument `prev` at flake.nix:99:33-76
-W EtaReduce

    {
      # When you have a function abstraction, only to immediately apply the
      # argument to a function, this is called an η-abstraction (or eta-abstraction)
      # See also: https://wiki.haskell.org/Eta_conversion
      bad = x: f x;

      # Generally, it nicer to be direct:
      good = f;
    }

I tried simplifying it to:

      overlays.default = (import ./overlays inputs);

But then nix flake check is not happy:

shell ❯ nix flake check                                                                                                                                                                    
error: overlay does not take an argument named 'final'
(use '--show-trace' to show detailed location information)

Is this a bug or am I misunderstanding the help message?

[Synthetica9]

No, you are correctly understanding the message. However, flake check doesn't only look at the semantics of the code (which are equal after this transformation), but also at the formatting. nix-linter has no flake-specific code to handle this, so it throws this warning.

As an aside, I think flake check should be a bit less stringent here, because the simplified code is perfectly reasonable.

[pinpox]

So basically I can't use the linter with flakes in their current state with that check? I have found other occurances that seem to have a similar problem. E.g. I'm not using the final: argument in the overlay, but flake check tells me I have to pass it.