Conflict between extraPackages and overrides

[jonathan-conder]

Describe the issue

I'm attempting to add python-lsp-ruff to extraPackages, but I get this error:

       error: attribute 'ruff' missing

       at /nix/store/lpqygnph8c5l7ajkmqr4rff0pvkfz1f6-source/overrides/default.nix:3229:9:

         3228|         in
         3229|         prev.ruff.overridePythonAttrs (old:
             |         ^
         3230|           let
       Did you mean one of cruft, daff, ruffus, runs or tuf?

The issue seems to be that ruff isn't in python3Packages, but the overlay assumes it is. Usually an earlier overlay will add it, from poetry.lock.

I found a workaround which I've left commented out below. If it suits I can make a PR to remove ruff from the overlay if prev.ruff doesn't exist. Or maybe the overlay shouldn't be applied to extraPackages? An alternative would be add ruff to python3Packages in nixpkgs.

Additional context

flake.nix:

{
  description = "MWE";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  inputs.poetry2nix.url = "github:nix-community/poetry2nix";

  outputs = {
    self,
    nixpkgs,
    poetry2nix,
  }: let
    toPackages = _: pkgs: let
      poetryLib = poetry2nix.lib.mkPoetry2Nix {inherit pkgs;};

      # overlay = final: prev: {inherit (pkgs) ruff;};
    in {
      default = poetryLib.mkPoetryEnv {
        projectDir = self;

        extraPackages = ps: [ps.python-lsp-ruff];

        # overrides = poetryLib.defaultPoetryOverrides.overrideOverlay overlay;
      };
    };
  in {
    packages = builtins.mapAttrs toPackages nixpkgs.legacyPackages;
  };
}

pyproject.toml:

[tool.poetry]
name = "mwe"
version = "0.1.0"
description = ""
authors = ["Your Name <you@example.com>"]
readme = "README.md"

[tool.poetry.dependencies]
python = "^3.11"

[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"

poetry.lock:

# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
package = []

[metadata]
lock-version = "2.0"
python-versions = "^3.11"
content-hash = "81b2fa642d7f2d1219cf80112ace12d689d053d81be7f7addb98144d56fc0fb2"