It has been years (literally) since I last debugged MorphOS on PUP, but IIRC there was a way (I think it was a log written to RAM which could later be recovered. I really ought to remember as it was me who did the early debugging and alpha testing to get MorphOS running on BPPC in the first place). Unfortunately I no longer have my Amiga up and running so I can't help much.
Perhaps someone over morphzone.org can help?