-- configure.in
++ configure.in
then
AC_MSG_CHECKING(whether gcc supports ParseTuple __format__)
save_CFLAGS=$CFLAGS
CFLAGS="$CFLAGS -Werror"
CFLAGS="$CFLAGS -Werror=format"
AC_COMPILE_IFELSE([
AC_LANG_PROGRAM([[void f(char*,...)__attribute((format(PyArg_ParseTuple, 1, 2)));]], [[]])
],[