Comment 27 for bug 532481

An additional run and using vmmap seems to confirm that the thread is running out of writable stack and attempting to store into the non-writable stack area:

Exception Codes: KERN_PROTECTION_FAILURE at 0x000000010e53ffc8

frame pointer (%rbp) = 0x10e540380
-0x3b8(%rbp) = 0x10e53ffc8

Virtual Memory Map of process 16452 (drizzled)
Output report format: 2.2 -- 64-bit process

==== Non-writable regions for process 16452
Stack 000000010e53f000-000000010e540000 [ 4K] r--/rwx SM=PRV thread 15

==== Writable regions for process 16452
Stack 000000010e540000-000000010e5c2000 [ 520K] rw-/rwx SM=PRV