--- a/Utilities/cmcurl/include/curl/multi.h	2021-02-12 21:03:08.726002327 +0330
+++ b/Utilities/cmcurl/include/curl/multi.h	2021-02-12 21:03:12.015764990 +0330
@@ -47,6 +47,7 @@
  * but with this warning attached.
  */
 #include "curl.h"
+#include <unistd.h>
 
 #ifdef  __cplusplus
 extern "C" {