"killThread" hangs! (ironic)

[Ryan Newton]

Hi,

This isn't a bug-report, but it's information gathering in preparation for one.

In testing the new "network-transport" communication layer, I've got a situation where killThreads hangs and I'm looking for possible explanations.  It's described in this issue ticket, with some instructions for reproducing:

    https://github.com/haskell-distributed/distributed-process/issues/7

Because killThread amounts to throwTo of a KillThread exception, I was initially thinking that there's something stopping the receiving thread from receiving the asynchronous exception?  (Like a tight, non-allocating loop?) 

But the pattern of GHC versions where the bug occurs is odd (i.e. non-monotonic!).  I'd appreciate knowing if anyone else sees the same results.

Best,
  -Ryan