diff -Naur Python-3.8.0-orig/setup.py Python-3.8.0/setup.py --- Python-3.8.0-orig/setup.py 2019-10-22 10:01:17.378172600 +0300 +++ Python-3.8.0/setup.py 2019-10-22 10:01:29.904994600 +0300 @@ -1667,7 +1667,12 @@ libraries=libs, include_dirs=["Modules/_multiprocessing"])) + multiprocessing_libs = [] + if MS_WINDOWS: + multiprocessing_libs += ['ws2_32'] self.add(Extension('_multiprocessing', multiprocessing_srcs, + define_macros={}, + libraries=multiprocessing_libs, include_dirs=["Modules/_multiprocessing"])) def detect_uuid(self):