This only happens on Win64, and appears to be a heisenbug.
Comment #1 by safety0ff.bugz — 2014-10-19T20:06:48Z
(In reply to Walter Bright from comment #0)
> This only happens on Win64, and appears to be a heisenbug.
The test is randomized and it seems it may have triggered the assertion on Darwin_64_32 as well:
https://auto-tester.puremagic.com/pull.ghtml?projectid=1&runid=1221126
The test should be changed such that it prints out the seed used for the RNG.
Comment #2 by safety0ff.bugz — 2014-10-22T02:52:23Z