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

[miss-islington]

https://github.com/python/cpython/commit/fafa213870193cf79557588ae8f9a4af570fd6e3
commit: fafa213870193cf79557588ae8f9a4af570fd6e3
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2021-09-29T06:47:56-07:00
summary:

bpo-44394: Ensure libexpat is linked against libm (GH-28617)

(cherry picked from commit 6c1154b9de29e1c9cd3d05f5289543e5cff73895)

Co-authored-by: Pablo Galindo Salgado <Pablogsal at gmail.com>

files:
M setup.py

diff --git a/setup.py b/setup.py
index 54d4b942bd5af..2bb71dde18d37 100644
--- a/setup.py
+++ b/setup.py
@@ -1686,7 +1686,9 @@ def detect_expat_elementtree(self):
                 ('XML_POOR_ENTROPY', '1'),
             ]
             extra_compile_args = []
-            expat_lib = []
+            # bpo-44394: libexpact 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']