From 5d8782b399b065d3989d583ca3743e7e41902cf8 Mon Sep 17 00:00:00 2001
From: Harinn <prinn.dev@pm.me>
Date: Sat, 16 May 2026 21:38:54 +0700
Subject: [PATCH] python3Packages.draccus: fix build with python 3.14

---
 pkgs/development/python-modules/draccus/default.nix | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/pkgs/development/python-modules/draccus/default.nix b/pkgs/development/python-modules/draccus/default.nix
index 02f3a89fa5a3..99bbcbd2c36c 100644
--- a/pkgs/development/python-modules/draccus/default.nix
+++ b/pkgs/development/python-modules/draccus/default.nix
@@ -39,6 +39,13 @@ buildPythonPackage rec {
     })
   ];
 
+  # Pass non-callable type= (typing.Union, X | Y) through argparse.
+  postPatch = ''
+    substituteInPlace draccus/wrappers/field_wrapper.py \
+      --replace-fail '_arg_options["type"] = tpe' \
+                     '_arg_options["type"] = tpe if callable(tpe) else str'
+  '';
+
   build-system = [
     setuptools
   ];