If no Step 5, the autoconf needs the GNU M4 1.4.16 or newer. However, I can not find the native M4 for MSYS. My M4 is 1.4.14. It is up-to-date in MSYS. $ m4 --v m4 (GNU M4) 1.4.14 Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gp...