Session(s) locking a pl/sql package

When you try to compile a package, some times you get following error

ORA-04021: timeout occurred while waiting to lock object <Your Package Name>

The query given below can give you information about session locking your package.

SELECT dli.*, vs.*
  FROM dba_lock_internal dli
     , v$session         vs
 WHERE dli.lock_id1 like '%:Package_Name%'
   AND vs.sid       =    dli.session_id
 ORDER BY session_id