Use the instrumenter method.

@instrumenter is not defined. It was moved to a method.

rails/rails@dc522a3

Author: andynu

lib/active_record/connection_adapters/oracle_enhanced/dbms_output.rb

@@ -32,7 +32,7 @@ def dbms_output_enabled?
 
       private
         def log(sql, name = "SQL", binds = [], type_casted_binds = [], statement_name = nil, async: false, &block)
-          @instrumenter.instrument(
+          instrumenter.instrument(
             "sql.active_record",
             sql:               sql,
             name:              name,