ruby-duckdb.h in duckdb-0.0.5

- old
+ new

@@ -1,9 +1,10 @@
 #ifndef RUBY_DUCKDB_H
 #define RUBY_DUCKDB_H
 
 #include "ruby.h"
 #include <duckdb.h>
+#include "./error.h"
 #include "./database.h"
 #include "./connection.h"
 #include "./result.h"
 
 extern VALUE mDuckDB;