Traditionally, you can use set error verbosity using error_reporting(E_ALL ^ E_NOTICE ^ E_DEPRECATED)
(i.e., report everything—except notices and deprecation warnings) as mentioned in "disabling deprecated errors".
Your issue may be related to CodeIgniter taking ownership of all errors.
system/core/CodeIgniter.php calls the function set_error_handler
. You can find and modify the function _exception_handler
it invokes on error in system/core/Common.php. It doesn't appear to be a configurable, so you may simply want to edit the line that begins with $is_error
.