From b618d8da31010bdc4ca5982768221352f03ae35a Mon Sep 17 00:00:00 2001
From: "Robert T. McGibbon" <rmcgibbo@gmail.com>
Date: Thu, 25 Mar 2021 15:48:59 -0400
Subject: [PATCH] python39Packages.asttokens: unbreak

---
 .../development/python-modules/asttokens/default.nix | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/python-modules/asttokens/default.nix b/pkgs/development/python-modules/asttokens/default.nix
index 0f090d14abada6..ecbbfa909112a8 100644
--- a/pkgs/development/python-modules/asttokens/default.nix
+++ b/pkgs/development/python-modules/asttokens/default.nix
@@ -1,4 +1,4 @@
-{ lib, fetchPypi, buildPythonPackage,
+{ lib, fetchPypi, fetchpatch, buildPythonPackage,
   setuptools_scm, toml, six, astroid, pytest
 }:
 
@@ -11,6 +11,16 @@ buildPythonPackage rec {
     sha256 = "0a2ixiz04aw4p0aivxh47k3fa9ql804l3y5iv5gcih9aizi5fbm4";
   };
 
+  patches = [
+    # Fixes compatibility with python 3.9, will be included in the next release
+    # after 2.0.4
+    (fetchpatch {
+      url = "https://github.com/gristlabs/asttokens/commit/d8ff80ee7d2e64c5e1daf50cc38eb99663f1b1ac.patch";
+      sha256 = "19y8n8vpzr2ijldbq5rh19sf0vz5azqqpkb9bx0ljjg98h6k7kjj";
+      excludes = [ "setup.cfg" ];
+    })
+  ];
+
   propagatedBuildInputs = [ setuptools_scm toml six astroid ];
 
   checkInputs = [ pytest ];