From fdaa3e9313ceb72f53af5541fa72c2ef3a5895fe Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Tue, 29 Dec 2020 06:05:08 -0800
Subject: [PATCH] Backport PR #38766: BLD: fix build failure py3.9.1 on OSX

---
 doc/source/whatsnew/v1.2.1.rst | 2 +-
 setup.py                       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/whatsnew/v1.2.1.rst b/doc/source/whatsnew/v1.2.1.rst
index 37562be17f02e..649b17e255f3d 100644
--- a/doc/source/whatsnew/v1.2.1.rst
+++ b/doc/source/whatsnew/v1.2.1.rst
@@ -41,7 +41,7 @@ I/O
 
 Other
 ~~~~~
--
+- Fixed build failure on MacOS 11 in Python 3.9.1 (:issue:`38766`)
 -
 
 .. ---------------------------------------------------------------------------
diff --git a/setup.py b/setup.py
index a25fe95e025b3..f9c4a1158fee0 100755
--- a/setup.py
+++ b/setup.py
@@ -435,7 +435,7 @@ def run(self):
             "MACOSX_DEPLOYMENT_TARGET", current_system
         )
         if (
-            LooseVersion(python_target) < "10.9"
+            LooseVersion(str(python_target)) < "10.9"
             and LooseVersion(current_system) >= "10.9"
         ):
             os.environ["MACOSX_DEPLOYMENT_TARGET"] = "10.9"