Weird behavior of the NonTermination exception

[Edward Z. Yang]

Excerpts from Bas van Dijk's message of Thu May 03 11:10:38 -0400 2012:
> As can be seen, the putMVar is executed successfully. So why do I get
> the message: "thread blocked indefinitely in an MVar operation"?

GHC will send BlockedIndefinitelyOnMVar to all threads involved
in the deadlock, so it's not unusual that this can interact with
error handlers to cause the system to become undeadlocked.

    http://blog.ezyang.com/2011/07/blockedindefinitelyonmvar/

However, I must admit I am a bit confused as for the timing of
the thrown exceptions.

Edward