working state up to location update and classmark inquiry

diff --git a/src/db_test.c b/src/db_test.c
index 27ddbab..0367ce2 100644
--- a/src/db_test.c
+++ b/src/db_test.c
@@ -21,6 +21,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <malloc.h>
 
 int main() {