Você provavelmente quer
DBMS_UTILITY.FORMAT_ERROR_BACKTRACE
função SQL> ed
Wrote file afiedt.buf
1 create or replace procedure p1
2 is
3 begin
4 raise_application_error( -20001, 'Error 1', true );
5* end;
SQL> /
Procedure created.
SQL> create or replace procedure p2
2 as
3 begin
4 null;
5 p1;
6 end;
7 /
Procedure created.
SQL> begin
2 p2;
3 exception
4 when others then
5 dbms_output.put_line( dbms_utility.format_error_backtrace );
6 end;
7 /
ORA-06512: at "SCOTT.P1", line 4
ORA-06512: at "SCOTT.P2", line 5
ORA-06512: at
line 2
PL/SQL procedure successfully completed.