fix crash in latest llvm

vinitkumar · vinitkumar · commit f0d30fc7d3ee · 2026-01-12T15:52:38.000+05:30
diff --git a/c/src/chatbot.c b/c/src/chatbot.c
@@ -1,3 +1,6 @@
+// Enable POSIX functions (strdup, strncasecmp, etc.)
+#define _POSIX_C_SOURCE 200809L
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
