commit 01df8861c19a203cea9ef26570893c2b9c0e48b2
Author: Evgeny Grin (Karlson2k) <k2k@narod.ru>
Date:   Wed Apr 12 21:11:28 2017 +0300

    Fixed GNU/Linux builds without epoll

diff --git a/src/microhttpd/daemon.c b/src/microhttpd/daemon.c
index 49a1b82..02713e3 100644
--- a/src/microhttpd/daemon.c
+++ b/src/microhttpd/daemon.c
@@ -2251,8 +2251,10 @@ send_param_adapter (struct MHD_Connection *connection,
       if (0 < ret)
         {
           /* write successful */
+#ifdef EPOLL_SUPPORT
           if (left > (uint64_t)ret)
             connection->epoll_state &= ~MHD_EPOLL_STATE_WRITE_READY;
+#endif /* EPOLL_SUPPORT */
           return ret;
         }
       err = MHD_socket_get_error_();