Packaging rpmlint

I’m trying to install rpmlint in order to install it in an overlay,

I have the following invocation:

{
  description = "BXI devel env";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-utils = {
      #inputs.nixpkgs.follows = "nixpkgs";
      url = "github:numtide/flake-utils";
    };
    devshell.url = "github:numtide/devshell";
    rpmlint = {
      url = "github:rpm-software-management/rpmlint";
      flake = false;
    };
  };

  outputs = { self, nixpkgs, flake-utils, ... }@inputs:
    flake-utils.lib.eachDefaultSystem (system:
      let
        rpmlint = pkgs.python3.pkgs.buildPythonPackage {
          pname = "rpmlint";
          version = "2.2";
          src = inputs.rpmlint;
          propagatedBuildInputs = with pkgs.python3.pkgs; [ zstandard pyxdg toml rpm ];
        };

        pkgs = import nixpkgs {
          inherit system;
          overlays = [
            inputs.devshell.overlay
            (self: super: {
              inherit rpmlint;
            })
          ];
        };
      in
      {
        devShell = pkgs.devshell.fromTOML ./devshell.toml;
      });

but this fails with the output

error: builder for '/nix/store/z5fcm6pwjhbzig97jv4va3sdinmmiqd7-python3.9-rpmlint-2.2.drv' failed with exit code 1;
       last 10 log lines:
       > Finished executing setuptoolsBuildPhase
       > installing
       > Executing pipInstallPhase
       > /build/source/dist /build/source
       > Processing ./rpmlint-2.2.0-py3-none-any.whl
       > Requirement already satisfied: zstandard in /nix/store/6j9g1g2ay486hr4brd5bfl4v8916ljii-python3.9-zstandard-0.17.0/lib/python3.9/site-packages (from rpmlint==2.2.0) (0.17.0)
       > Requirement already satisfied: pyxdg in /nix/store/0nfnz023z8347y2kgmxj7c505da3fw5w-python3.9-pyxdg-0.27/lib/python3.9/site-packages (from rpmlint==2.2.0) (0.27)
       > Requirement already satisfied: toml in /nix/store/bamzq0w4lra7lgamym14j3qjmbb2ynnc-python3.9-toml-0.10.2/lib/python3.9/site-packages (from rpmlint==2.2.0) (0.10.2)
       > ERROR: Could not find a version that satisfies the requirement rpm (from rpmlint) (from versions: none)
       > ERROR: No matching distribution found for rpm
       For full logs, run 'nix log /nix/store/z5fcm6pwjhbzig97jv4va3sdinmmiqd7-python3.9-rpmlint-2.2.drv'.
error: 1 dependencies of derivation '/nix/store/fhiv75a4c8hmwcdh2vs2mn9473hdymym-devshell-dir.drv' failed to build
error: 1 dependencies of derivation '/nix/store/ax0scspllc8h20l0jcp976c82n27m8mp-devshell-env.drv' failed to build

I don’t understand why it the rpm python package is not picked up when the others are…