Seg Fault when printing thread.keys
This is very easy to reproduce:
for thr in Thread.list
Somehow a key is introduced to the thread with the object ID of 8.
Attempting to inspect or to_s this key results in a seg fault.
1.9.3p194 :001 > ObjectSpace._id2ref(8)
RangeError: 0x00000000000008 is not symbol id value
It is not clear how this object is created or inserted into the Thread.