Add poetry2nix to flake inputs and use it

Fixes #441

flake.nix

@@ -6,6 +6,10 @@
       flake = false;
     };
     flake-utils.url = "github:numtide/flake-utils";
+    poetry2nix = {
+      url = "github:nix-community/poetry2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
   outputs = { nixpkgs, flake-utils, ... }:
     flake-utils.lib.eachDefaultSystem (system:

testing/python/MODULE.bazel

@@ -49,6 +49,7 @@ use_repo(non_module_deps, "nixpkgs")
 use_repo(non_module_deps, "nixpkgs_python_toolchain")
 use_repo(non_module_deps, "nixpkgs_python_configure_test")
 use_repo(non_module_deps, "nixpkgs_python_toolchain_python3")
+use_repo(non_module_deps, "poetry2nix")
 register_toolchains("@nixpkgs_python_toolchain//:all")
 
 use_repo(non_module_deps, "generated_poetry_packages_deps")

testing/python/poetry.nix

@@ -1,6 +1,7 @@
 let
-  nixpkgs = import <nixpkgs> {};
-  inherit (nixpkgs) lib poetry2nix python3 runCommand;
+  nixpkgs = import <nixpkgs> { };
+  poetry2nix = import <poetry2nix> { pkgs = nixpkgs; };
+  inherit (nixpkgs) python3;
 
   args = {
     python = python3;

testing/python/poetry2nix.nix

@@ -0,0 +1,12 @@
+let
+  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  poetry2nix =
+    let
+      src = lock.nodes.poetry2nix.locked;
+    in
+    assert src.type == "github";
+    fetchTarball {
+      url = "https://github.com/${src.owner}/${src.repo}/archive/${src.rev}.tar.gz";
+      sha256 = src.narHash;
+    };
+in import poetry2nix

testing/python/tests/nixpkgs_repositories.bzl

@@ -11,6 +11,12 @@ def nixpkgs_repositories(*, bzlmod):
         nix_file_deps = ["//:flake.lock"],
     )
 
+    nixpkgs_local_repository(
+        name = "poetry2nix",
+        nix_file = "//:poetry2nix.nix",
+        nix_file_deps = ["//:flake.lock"],
+    )
+
     # Tests implicitly depend on Java
     nixpkgs_java_configure(
         name = "nixpkgs_java_runtime",
@@ -43,7 +49,10 @@ def nixpkgs_repositories(*, bzlmod):
 
     nixpkgs_python_repository(
         name = "poetry_packages",
-        repository = "@nixpkgs",
+        repositories = {
+            "nixpkgs": "@nixpkgs",
+            "poetry2nix": "@poetry2nix",
+        },
         nix_file = "//:poetry.nix",
         nix_file_deps = [
             "//:pyproject.toml",