From a686f74d9441c53088fef6b847cd1e7404960c29 Mon Sep 17 00:00:00 2001
From: Joshua Oreman <oremanj@gmail.com>
Date: Tue, 4 Jun 2019 01:35:05 -0700
Subject: [PATCH] Fix closure cell rewriting on 3.8 (#539)

* Fix closure cell rewriting on 3.8

* Enable py38

* Don't use CodeType.replace() -- it was added in 3.8.0b1, but CI still uses 3.8.0a4
---
 azure-pipelines.yml | 7 +++----
 src/attr/_compat.py | 2 ++
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 5ad92cc5..f498a90d 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -30,10 +30,9 @@ jobs:
         py37:
           python.version: '3.7'
           tox.env: py37
-        # Our cell rewriting is currently broken on 3.8.
-        # py38:
-        #   python.version: '3.8'
-        #   tox.env: py38
+        py38:
+          python.version: '3.8'
+          tox.env: py38
 
         pypy2:
           python.version: 'pypy2'
diff --git a/src/attr/_compat.py b/src/attr/_compat.py
index efd1eb52..a0df333b 100644
--- a/src/attr/_compat.py
+++ b/src/attr/_compat.py
@@ -164,6 +164,8 @@ def make_set_closure_cell():
         # Convert this code object to a code object that sets the
         # function's first _freevar_ (not cellvar) to the argument.
         args = [co.co_argcount]
+        if sys.version_info >= (3, 8):
+            args.append(co.co_posonlyargcount)
         if not PY2:
             args.append(co.co_kwonlyargcount)
         args.extend(