diff -Naur Python-2.7.9-orig/Lib/distutils/cygwinccompiler.py Python-2.7.9/Lib/distutils/cygwinccompiler.py --- Python-2.7.9-orig/Lib/distutils/cygwinccompiler.py 2014-12-11 13:50:54.147800000 +0300 +++ Python-2.7.9/Lib/distutils/cygwinccompiler.py 2014-12-11 13:51:21.245000000 +0300 @@ -330,9 +330,9 @@ else: no_cygwin = '' - self.set_executables(compiler='gcc%s -O -Wall' % no_cygwin, - compiler_so='gcc%s -mdll -O -Wall' % no_cygwin, - compiler_cxx='g++%s -O -Wall' % no_cygwin, + self.set_executables(compiler='gcc%s -O2 -Wall' % no_cygwin, + compiler_so='gcc%s -mdll -O2 -Wall' % no_cygwin, + compiler_cxx='g++%s -O2 -Wall' % no_cygwin, linker_exe='gcc%s' % no_cygwin, linker_so='%s%s %s %s' % (self.linker_dll, no_cygwin,