From 3777863672bd52bfe9d561764152612a4dd0eaad Mon Sep 17 00:00:00 2001
From: Robert Scott <code@humanleg.org.uk>
Date: Tue, 1 Jun 2021 13:00:01 +0100
Subject: [PATCH] python3Packages.starlette: fix build

newer python 3.8+ releases expose this breakage
https://github.com/encode/starlette/issues/1131, fixed upstream in
https://github.com/encode/starlette/pull/1132
---
 pkgs/development/python-modules/starlette/default.nix | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/pkgs/development/python-modules/starlette/default.nix b/pkgs/development/python-modules/starlette/default.nix
index ff8a93d335ea9..7fedb3f3ed114 100644
--- a/pkgs/development/python-modules/starlette/default.nix
+++ b/pkgs/development/python-modules/starlette/default.nix
@@ -2,6 +2,7 @@
 , stdenv
 , buildPythonPackage
 , fetchFromGitHub
+, fetchpatch
 , aiofiles
 , graphene
 , itsdangerous
@@ -31,6 +32,16 @@ buildPythonPackage rec {
     sha256 = "11i0yd8cqwscixajl734g11vf8pghki11c81chzfh8ifmj6mf9jk";
   };
 
+  patches = [
+    # a fix for https://github.com/encode/starlette/issues/1131 exposed
+    # by newer python 3.8+ versions
+    (fetchpatch {
+      name = "dont-use-undocumented-tracebackexception-attr.patch";
+      url = "https://github.com/encode/starlette/pull/1132/commits/aa97f30c73e1c830e0952f7a97d08bc5fad03dea.patch";
+      sha256 = "0clf8l4606y1g585dg4gvx250s2djskji8jaim4s90l9xzjag8sb";
+    })
+  ];
+
   propagatedBuildInputs = [
     aiofiles
     graphene