[GHC] #13601: GHC errors but hangs

[GHC]

#13601: GHC errors but hangs
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:  TypeInType,
                                     |  LevityPolymorphism
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by RyanGlScott):

 This appears to be fixed in GHC HEAD. I need to figure out which commit
 did the deed.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13601#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler