Error-Prone Error Handling ....oracle

A colleague found this handy utility on the internet. The idea is that whenever you get an Oracle error, the errant SQL statement will be written away to a table along with the message for you to read and enjoy at your leisure. Which would be fine I suppose, if it didn't introduce a whole lot of errors of its own.

create table caught_errors (
 dt        date,              
 username  varchar2( 30), -- value from ora_login_user
 msg       varchar2(512),
 stmt      varchar2(512)
);

create or replace trigger catch_errors
  after servererror on database
declare
  sql_text ora_name_list_t;
  msg_     varchar2(2000) := null;
  stmt_    varchar2(2000) := null;
begin

 for depth in 1 .. ora_server_error_depth loop
   msg_ := msg_ || ora_server_error_msg(depth);
 end loop;

 for i in 1 .. ora_sql_txt(sql_text) loop
    stmt_ := stmt_ || sql_text(i);
 end loop;

 insert into
   caught_errors (dt     , username      ,msg ,stmt )
          values (sysdate, ora_login_user,msg_,stmt_);
end;
/

Note that whenever a SQL error occurs on the database this trigger will fire and:

1) try to stuff the entire SQL statement that failed into a varchar2(2000), regardless of how big it actually is

2) if that doesn't blow up, then tries to insert the same value into a varchar2(255) column

In SQL Plus, this leads to errors like this (using an invalid table name in a large SELECT statement):

ERROR at line 30:
ORA-00604: error occurred at recursive SQL level 1
ORA-01401: inserted value too large for column
ORA-06512: at line 12
ORA-00942: table or view does not exist

... which is clearly more informative than:

ERROR at line 30:
ORA-00942: table or view does not exist