From 9732946b82f9e064603a31d3591783e867b7359c Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sat, 15 Feb 2020 08:43:20 -0500
Subject: Avoid installing setuptools 45 on Python 2.

Because Requires-Python is disabled for Python 2 to allow this declared-incompatible version to install on Python 2, the build-requirements must exclude installing setuptools 45 during the build-system setup.

Because Python 2 tests are only needed for internal validation, and because the latest pip is already installed, the build-system can rely on `backend-path = ["."]`.

Fixes #1996.
---
 pyproject.toml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index f0fd8521..cfdc2574 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,9 @@
 [build-system]
-requires = ["setuptools >= 40.8", "wheel"]
+requires = [
+    # avoid self install on Python 2; ref #1996
+    "setuptools >= 40.8; python_version > '3'",
+    "wheel",
+]
 build-backend = "setuptools.build_meta"
 backend-path = ["."]
 
-- 
cgit v1.2.3