I saw dumplog text in a newsgroup posting and the only way I could
recognize what version generated it was that "You entered the dungeon
N turns ago" included the missing-until-recently final period. So,
put nethack's one-line version information as the very first dumplog
text and follow it with the dumped game's start and end date+time.
(That information is useful to know in its own right, but also should
prevent the build date+time shown with the version from confusing
anybody about when the dump was written.)
Along the way, I noticed that the 'counting' phase for artifact_score
was being repeated for '#if DUMPLOG' even though it doesn't generate
output. That had a side-effect of adding points for artifacts twice
(applicable when final score was for an ascension or dungeon escape).