From d347164e04b75220747a236d6fc5d156dce2d313 Mon Sep 17 00:00:00 2001
From: Daniel Edgecumbe <git@esotericnonsense.com>
Date: Mon, 4 Jan 2021 17:03:58 +0000
Subject: [PATCH] libcst: fix python 3.6 support

The 'dataclasses' module is a required dependency of libcst.
Python >= 3.7 include this module natively.
---
 pkgs/development/python-modules/libcst/default.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/python-modules/libcst/default.nix b/pkgs/development/python-modules/libcst/default.nix
index e0ea0e332af6..f064c34e1586 100644
--- a/pkgs/development/python-modules/libcst/default.nix
+++ b/pkgs/development/python-modules/libcst/default.nix
@@ -1,5 +1,5 @@
 { lib, buildPythonPackage, fetchFromGitHub, pythonOlder, black, isort
-, pytestCheckHook, pyyaml, typing-extensions, typing-inspect }:
+, pytestCheckHook, pyyaml, typing-extensions, typing-inspect, dataclasses }:
 
 buildPythonPackage rec {
   pname = "libcst";
@@ -16,7 +16,8 @@ buildPythonPackage rec {
 
   disabled = pythonOlder "3.6";
 
-  propagatedBuildInputs = [ pyyaml typing-inspect ];
+  propagatedBuildInputs = [ pyyaml typing-inspect ]
+    ++ lib.optional (pythonOlder "3.7") dataclasses;
 
   checkInputs = [ black isort pytestCheckHook ];