[GHC] #12521: Thread blocked indefinitely in an MVar operation

[GHC]

#12521: Thread blocked indefinitely in an MVar operation
-------------------------------------+-------------------------------------
        Reporter:  SwiftsNamesake    |                Owner:
            Type:  bug               |               Status:  infoneeded
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.8.4
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  GHCi crash        |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by SwiftsNamesake):

 * I'm using Windows 10.
 * chcp is a windows command which changes the active code page

 I was trying to print Unicode characters.

 I launched the Windows console (cmd), started GHCi, ran that putStrLn-
 snippet and (obviously) got an exception.

 I don't remember exactly but I must've terminated GHCi (:q), changed the
 code page and then restarted GHCi to try again (in quick succesion). I
 remember the commands from cmd and GHCi being 'interleaved' (ie. things I
 started typing into the CMD appeared inside GHCi later on).

 It's possible that it's really CMD which is at fault but I decided to
 report it anyway since I was asked to.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12521#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler