From b2e5b6048877b2cd4f809ccb17b8aa2a30d51e92 Mon Sep 17 00:00:00 2001
From: Willy <jemand771@gmx.net>
Date: Wed, 22 Jul 2026 23:31:43 +0200
Subject: [PATCH] python3Packages.protobuf4: fix for setuptools >= 81

`pkg_resources` was finally removed, use `packaging` for parsing version strings instead

this is the recommended approach from setuptools' docs: https://setuptools.pypa.io/en/latest/deprecated/pkg_resources.html
---
 pkgs/development/python-modules/protobuf/4.nix | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/python-modules/protobuf/4.nix b/pkgs/development/python-modules/protobuf/4.nix
index 9e88591bb108..4ba55804e1db 100644
--- a/pkgs/development/python-modules/protobuf/4.nix
+++ b/pkgs/development/python-modules/protobuf/4.nix
@@ -6,6 +6,7 @@
   lib,
   stdenv,
   numpy,
+  packaging,
   protobuf,
   pytestCheckHook,
   pythonAtLeast,
@@ -68,9 +69,18 @@ buildPythonPackage {
     + ''
       substituteInPlace google/protobuf/internal/json_format_test.py \
         --replace-warn assertRaisesRegexp assertRaisesRegex
+    ''
+    # setuptools 81 dropped pkg_resources, parse versions via packaging module
+    + ''
+      substituteInPlace setup.py \
+        --replace-fail "import pkg_resources" "import packaging.version" \
+        --replace-fail "pkg_resources.parse_version" "packaging.version.parse"
     '';
 
-  nativeBuildInputs = lib.optional isPyPy tzdata;
+  nativeBuildInputs = [
+    packaging
+  ]
+  ++ lib.optional isPyPy tzdata;
 
   buildInputs = [ protobuf ];