Regarding the patching of configure script, there must be something
wrong with the automake (or is it autoconf) on this machine.
The logic for setting NN_HAVE_EVENTFD works, and the logic for
NN_USE_EVENTFD seems ok. But even though it correctly finds that eventfd
doesn't exist on the system, it still sets NN_USE_EVENTFD.
AS_IF([test x"$ac_cv_func_eventfd"=xyes], [
AC_DEFINE([NN_USE_EVENTFD])], [
AS_IF([test x"$ac_cv_func_pipe"=xyes], [
AC_DEFINE([NN_USE_PIPE])], [
AS_IF([test x"$ac_cv_func_socketpair"=xyes], [
AC_DEFINE([NN_USE_SOCKETPAIR])], [
AC_MSG_ERROR([No signaling supported])
])
])
])
As expected, $ac_cv_func_eventfd has value "no".
