diff -ruw source/lib/nonblock.c source-new/lib/nonblock.c
--- source/lib/nonblock.c	2018-10-27 04:00:54.000000000 -0600
+++ source-new/lib/nonblock.c	2018-12-10 12:40:21.350755609 -0700
@@ -47,7 +47,7 @@
 int curlx_nonblock(curl_socket_t sockfd,    /* operate on this */
                    int nonblock   /* TRUE or FALSE */)
 {
-#if defined(USE_BLOCKING_SOCKETS)
+#if defined(USE_BLOCKING_SOCKETS) || defined(__redox__)
   (void)sockfd;
   (void)nonblock;
   return 0; /* returns success */
Only in source-new/lib: nonblock.c.orig
Only in source-new/lib: nonblock.c.rej