SQL> create or replace procedure p_test as
  2    l_deptno emp.deptno%type;
  3  begin
  4    select deptno
  5      into l_deptno
  6      from emp;
  7  end;
  8  /

Procedure created.

SQL> exec p_test;
BEGIN p_test; END;

*
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at "SCOTT.P_TEST", line 4                                      --> here!
ORA-06512: at line 1


SQL>

SQL> set serveroutput on;
SQL> CREATE OR replace PROCEDURE P_test
  2  AS
  3    l_deptno emp.deptno%TYPE;
  4  BEGIN
  5      SELECT deptno
  6      INTO   l_deptno
  7      FROM   emp;
  8  EXCEPTION
  9    WHEN OTHERS THEN
 10               dbms_output.Put_line ('---------------------');
 11
 12               dbms_output.Put (dbms_utility.format_error_stack);
 13
 14               dbms_output.Put (dbms_utility.format_error_backtrace);
 15
 16               dbms_output.Put_line ('---------------------');
 17
 18               RAISE;
 19  END;
 20
 21  /

Procedure created.

SQL> sho err;
No errors.
SQL> exec p_test;
---------------------
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at
"SCOTT.P_TEST", line 5
---------------------
BEGIN p_test; END;

*
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at "SCOTT.P_TEST", line 18
ORA-06512: at line 1

SQL>

*
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at "SCOTT.P_TEST", line 18                                 --> this is still wrong line number of error
ORA-06512: at line 1