--- vlc-3.0.20/configure.ac.orig
+++ vlc-3.0.20/configure.ac
@@ -307,6 +307,7 @@
     ;;
   solaris*)
     SYS=solaris
+    AC_DEFINE([_XOPEN_SOURCE], [600], [POSIX and XPG 6th edition])
     ;;
   hpux*)
     SYS=hpux