Typically, development databases are not started in archivelog mode. This causes a problem for hot backups but not necessarily for flashback queries.
You can still flashback to any time within the online redo logs:
alter session set nls_timestamp_format = 'dd-mon-yyyy hh24:mi:ss.ff3';
set lines 9999
set trims on
set pages 9999
set headi off
spool old_version.sql
select text
from dba_source
as of timestamp to_timestamp('22-sep-2011 07:30:00.000')
where 1=1
and owner = 'scott'
and name = 'mypackage'
order by type
, line;
spool off