From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; Latest mingw64 can provide *printf functions which support GNU format specifiers. It won't do that unless you have defined __USE_MINGW_ANSI_STDIO though. GNULIB's 'asprintf' module detected that mingw had the asprintf function, but didn't define the __USE_MINGW_ANSI_STDIO so we got left with the version offering Win32 format specifiers, instead of GNU formats. It could perhaps be argued that gnulib's 'asprintf' could be defining __USE_MINGW_ANSI_STDIO for us ? Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- configure.ac | 3 +++ 1 file changed, 3 insertions(+) diff --git a/configure.ac b/configure.ac index 3f3f11e..fe916d1 100644 --- a/configure.ac +++ b/configure.ac @@ -2123,6 +2123,9 @@ AC_SUBST([VERSION_SCRIPT_FLAGS]) AC_SUBST([MSCOM_LIBS]) +dnl http://sourceforge.net/apps/trac/mingw-w64/wiki/gnu%20printf +AC_DEFINE_UNQUOTED([__USE_MINGW_ANSI_STDIO], 1, [Enable GNU style printf formatters]) + dnl Look for windres to build a Windows icon resource. case "$host" in *-*-mingw* | *-*-cygwin* | *-*-msvc* ) -- 1.8.2.1