Use the exception command to display an exception’s type at any time during debugging. If you use the exception command without an option, the type shown is determined by the setting of the dbx environment variable output_dynamic_type:
If it is set to on, the derived type is shown.
If it is set to off (the default), the static type is shown.
Specifying the -d or +d option overrides the setting of the environment variable:
If you specify -d, the derived type is shown.
If you specify +d, the static type is shown.
For more information, see exception Command.