When you use your own output format, that all messages has the same format.

When you use:
-"format=%f %l %t %n; %m"

some messages looks like:
0 Info 766; Header file 'C:\projects\temp.h' not
used in module 'C:\projects\test.c'

or

0 Info 714; Symbol
'eGetInternal_Extended(void)' (line 3988, file
C:\projects\test.c) not referenced

At this outputs I´m missing the file name and line number at beginn of the message. But there are known at the end of the messages.

It´s hard to write a clean error parser, when the output messages changes.