Enable All Compilation Warnings

ALTER SESSION SET PLSQL_WARNINGS='ENABLE:ALL'

CREATE OR REPLACE PACKAGE pack5 AUTHID DEFINER AS  
PRAGMA DEPRECATE(pack5 , 'Package pack5 has been deprecated, use new_pack5 instead.');  
 PROCEDURE foo;  
 PROCEDURE bar;  
 END pack5; 

CREATE OR REPLACE PACKAGE BODY pack5 AS 
 PROCEDURE foo AS 
 BEGIN 
  DBMS_OUTPUT.PUT_LINE('Executing foo.'); 
 END foo; 
 PROCEDURE bar IS 
 BEGIN 
  DBMS_OUTPUT.PUT_LINE('Executing bar.'); 
 END bar; 
END; 

EXEC pack5.bar

CREATE OR REPLACE PACKAGE pack6 AUTHID DEFINER AS  
 PROCEDURE proc3;  
 END pack6; 

CREATE OR REPLACE PACKAGE BODY pack6 AS 
 PROCEDURE proc3 AS 
 BEGIN 
   pack5.foo; 
 END proc3; 
END; 

EXEC pack6.proc3

Display All Compilation Warnings for Units PACK5 and PACK6

SELECT * FROM USER_ERRORS WHERE NAME IN ('PACK5','PACK6')