code: def _enum_member_error(err, eid, name, value, bitmask):
      
      exception, msg = ENUM_ERROR_MAP[err]
      enum_name = idaapi.get_enum_name(eid)
      return exception(('add_enum_member(enum="{}", member="{}", value={}, bitmask=0x{:08X}) '
                        'failed: {}').format(
          enum_name,
          name,
          value,
          bitmask,
          msg
      ))
docs: Format enum member error.