[Python-checkins] [3.8] bpo-44394: Ensure libexpat is linked against libm (GH-28617) (GH-28620)

[ambv]

https://github.com/python/cpython/commit/90004fca1cc3c6e3c9b2c3faae5cb1b7d7711648
commit: 90004fca1cc3c6e3c9b2c3faae5cb1b7d7711648
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: ambv <lukasz at langa.pl>
date: 2021-09-29T16:35:53+02:00
summary:

[3.8] bpo-44394: Ensure libexpat is linked against libm (GH-28617) (GH-28620)

(cherry picked from commit 6c1154b9de29e1c9cd3d05f5289543e5cff73895)

Co-authored-by: Pablo Galindo Salgado <Pablogsal at gmail.com>
Co-authored-by: Łukasz Langa <lukasz at langa.pl>

files:
M setup.py

diff --git a/setup.py b/setup.py
index 2d6b05682d2ba..57be07a7e0f82 100644
--- a/setup.py
+++ b/setup.py
@@ -1578,7 +1578,9 @@ def detect_expat_elementtree(self):
                 ('XML_POOR_ENTROPY', '1'),
             ]
             extra_compile_args = []
-            expat_lib = []
+            # bpo-44394: libexpat uses isnan() of math.h and needs linkage
+            # against the libm
+            expat_lib = ['m']
             expat_sources = ['expat/xmlparse.c',
                              'expat/xmlrole.c',
                              'expat/xmltok.c']