Short: slow_shut_down is not used Date: 981209 Type: Bug State: Done - fixed in 3.2.8-dev.217 When the driver runs out of memory, it rapidly uses up all reserves and then aborts. Something somehow eats memory fast enough to prevent slow_shut_down from being reached at all. This is certainly the case when the garbage_collector runs into a MAX_MALLOCED limit when swapping in all the objects. 3.2.8-dev.202 added an additional diagnostic for this case, printing the amount of memory requested. The reason: if the driver ran out of memory in a small block allocation during a GC, the reserves were freed but the allocator didn't check the freelists after doing so.