Reported directly to devteam: a fake player monster was petrified
and when creating its statue yielded "Calculating weight of 0 gold
pieces?".
Fake player monsters on the Astral Plane level were being created
with rn2(1000) gold pieces so had a 1 in 1000 chance of that being 0.
Gold gets created with a non-zero amount but the routine that gives
it to a monster sets the amount to the requested value. That didn't
update the weight so didn't notice the 0. Putting it into a container
(the statue) did recalculate the weight and did notice.
There was a choice between forcing a non-zero amount or allowing 0
and bypassing its creation and placement in monster's inventory.
I went with the latter.