.

src/hostname.c

@@ -82,6 +82,9 @@ main (argc, argv)
 	error (1, errno, "%s", argv[1]);
       exit (0);
     }
+#else
+  if (argc == 2)
+    error (1, 0, "cannot set hostname; this system lacks the system call");
 #endif
 
   if (argc == 1)