From e16d93d7dfe7032ffc587adaf5179392dcdb4608 Mon Sep 17 00:00:00 2001
From: Paul Ganssle <paul@ganssle.io>
Date: Tue, 26 Feb 2019 12:13:49 -0500
Subject: [PATCH] Add PEP 517 to pyproject.toml

This puts a new minimum on the PEP 518 requirement for `setuptools`
because older versions of setuptools' PEP 517 backend will fail to
include `setup.py` in an sdist.
---
 pyproject.toml | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 7d64f993a3ec..21475bbb9664 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,10 @@
 [build-system]
-# Must be kept in sync with `setup_requirements` in `setup.py`
 requires = [
-    "setuptools>=18.5",
+    # The minimum setuptools version is specific to the PEP 517 backend,
+    # and may be stricter than the version required in `setup.py`
+    "setuptools>=40.6.0",
     "wheel",
+    # Must be kept in sync with the `setup_requirements` in `setup.py`
     "cffi>=1.8,!=1.11.3; python_implementation != 'PyPy'",
 ]
+build-backend = "setuptools.build_meta"